Gardening Tip of the Week
Time to Plant Strawberries
Strawberries are hardy perennials that come back to produce fruit for 3 to 5 years. So select a sunny, well-drained site you can pull out of your crop rotation for several years. Otherwise, select a container that you can keep well-watered and place in a sunny place. Strawberries need a lot of sun!
Secure bare-root or container grown-plants. When planting, locate the crown at the center of the plant and bury the roots so that soil line is just at the base of the crown and the roots are spread out. Any deeper and you risk the crown rotting, more shallow and the plant may dry out. Spacing will vary by variety, so check the specific recommendations for your plants.
Mulch between all strawberry plants with straw or chopped leaves. This will help to prevent the strawberries from rotting – a common problem when the fruit is in direct contact with the soil. Water thoroughly and keep the bed mulched and weeded through the growing season.
Most strawberry varieties produce runners, which can be trained to take root in a bare batch or, once rooted, transplanted to populate a new bed. However, clipping runners and pinching off early flowers will direct the plants’ growth into their roots, making for a more vigorous plants and better harvests later (but less fruit early in the year). With June-bearing varieties, it is best to pinch off the 1st season’s flowers. Though difficult, sacrificing the 1st year’s usually underwhelming harvest will greatly improve the 2nd year’s.
Starting Tomatoes Indoors
This week marks the five-week countdown until our last average frost date of April 15. If you haven’t yet started your tomatoes indoors, now is the perfect time. Tomatoes typically should be started indoors 6-8 weeks before being transplanted, and transplanted about 1-2 weeks after the last frost date for best success.
Keep seedlings warm using a propagation mat (or by putting the planting tray on top of the fridge). Most tomato varieties need about 75⁰ F for best germination rates. Remember that close lighting (1-2 inches) will keep them from getting leggy.
Transfer tomato seedlings into larger pots when they are 2-3 inches tall and have several sets of leaves. At this point, you’ll want to decrease watering to allow some drying to occur between watering. Also, take care to keep the foliage dry to limit the risk of fungus and disease outbreaks.
Winter Project: Make Your Garden Hospitable to Beneficial Insects
Consider constructing a bug hotel or bluebird house to provide shelter for local wildlife! The bug hotel gives beneficial insects a place to reside, even hibernate. It is easily built from upcycled and reclaimed materials and can be as simple or complex as you would like. You can construct a box or use a container you already have. Gather bamboo canes, sticks, seed pods, leaves and other organic materials from you home and garden. Using multiple fill materials with varying depths and surfaces will help attract a several different insects and spider species.
Arrange the material in the box with the ends of the canes, sticks, and leaves oriented toward the opening of the container in a visually appealing way (the open side will show!). Make sure the material is not sticking out past the edge of your container so that is doesn’t funnel water into the bug hotel. Add a roof or eave to your container for additional protection. See an example of this project here. Next time you visit your garden, mount the hotel with the open side perpendicular to the ground.
Get a Jump on Spring Planting with Row Covers, Hoop Beds, and Cold Frames
You can start your cold weather crops outdoors in the next couple of weeks if you add row covers, hoop beds, or a cold frame to your garden. Covers, hoop beds, and frames are all designed to warm the soil and protect early crops from frost. Don’t rush to put out tender plants just yet, but plan ahead and your cool weather greens will flourish with a little extra warmth and protection.
Adding a hoop cover to an existing raised bed in an easy and inexpensive project. Feed 1/2″ PVC pipe through pipe straps attached every 3-4′ to the outside of a long side of the bed frame. Bend the PVC over the bed and feed it through corresponding straps on the opposite side of the bed.
Lay plastic sheeting (minimum of 3.5 mil thickness) over the PVC frame and weigh down long edges with bricks, stones, or filled water bottles or milk jugs. Alternatively, sandwich the long edges of the sheeting between two pieces of lathe or other thin strips of wood and secure the wood to the outside of the bed. This has the added benefit of providing a rigid core to roll the sheeting up to access the bed and for storing over the summer.
Use clamps to gather and close ends for easy access and venting on warm days.
Growing Onions Indoors
If you are planning to grow onions indoors or in cold frames this spring, plant now! The easiest way to start onions is to fill a typical seedling flat or waterproof tray (with holes for drainage) with potting soil and sow seeds thickly.
If you want bulb onions, choose seed varieties that are best at our latitude (38⁰), since most onions are dependent on day length to produce a bulb. “Intermediate-day onions” are a good choice for the St. Louis area. As the seedlings grow, they can be pulled apart and potted or planted in the garden, about 4-6 weeks before the last frost date (April 15).
Purchasing seed this winter? Consider pelleted seed! Lettuce, carrot, and onion seeds can be so small that they can be difficult to seed properly, causing a need for excessive thinning later. Pelleted seeds are coated and much larger than normal, making it easy to sow only the amount you need.
Did you know? A wide variety of seed packets are for sale ($0.25 per packet) at the Gateway Greening Carriage House on Saturdays, from 9 AM – Noon, starting he first weekend in March. Visit us at 3815 Bell Ave on March 3rd to stock up and explore what is growing in the Demonstration Garden!
Extreme Winter Drought Alert!
According to Patrick Guinan, Extension/State Climatologist for the University of Missouri, this winter has been the driest on record in nearly three decades. Our friends at the Missouri Green Industry Alliance (MoGIA) are seeing signs of drought stress in turfs, trees, shrubs, and perennials throughout the St. Louis region, and are encouraging gardeners and homeowners to take advantage of warm days to provide extra water to plants.
Learn more by reading MoGIA’s Media Release.
Starting Cool Season Vegetable Transplants
Most cool-season transplants require about six weeks of indoor growth before being transferred outside. This means, the end of January is a good time to plant your first seeds. Start by looking at a good reference document that outlines the materials, time, and space required to grow healthy transplants for home gardens. Do you have enough space and materials for everything you wish to grow? Lighting, access to water, and warmth will be the most important factors to consider.
A heat mat is usually sufficient for warming the soil, which is often more important than warm air. For beginners, using a pre-mixed potting soil will make life easier. A good, light and fluffy potting soil that is evenly moistened before planting is ideal. For more advanced gardeners, plenty of recipes are online to make your own mix. Peat pellets and small greenhouse kits can save you money; just remember to invest in a water-soluble fertilizer to begin adding to your watering can once the seedlings have grown out their first set of true leaves.
If you still have carrots in the ground, try leaving them there to harvest throughout the winter. By using a deep layering of straw or leaf mulch (4-8″), you can keep the roots from freezing or heaving in the ground. It might help to mark their place with a stick or colored marker in case the green vegetation dies back during winter.
As the carrots concentrate sugars to survive the winter, you might also find that their taste will improve, especially over those grown during the warmer months. Since they are a biennial, it will be important to pull them up before next spring, since once they flower the root will become inedible.
Forcing Root Vegetables in Winter
An interesting technique for growing vegetables through the winter is called “forcing”. This is used primarily with root vegetables that are harvested from the garden just before the ground freezes. Cleaned roots (beets, turnips, celeriac, etc.) are planted in moist sand or compost and set on a window sill. From the stored energy in the roots, edible greens are produced that can accent a winter dish or be added to salads. This may also work with a harvested cabbage plant: pull the entire thing, roots and all, from the garden and cut off the head. Then plant it in moist sand in the window. Harvest the greens as they sprout this winter!
Spring Cabbage Experiment
Here’s a trick to try with those cabbages left in your garden bed. When the head is ready to harvest, cut it off at the base of the stem and leave the stump in the ground. Chop up some leaves with the lawnmower and pile up around the cabbage base, leaving the top of the stump uncovered. In early spring, you just might get some Brussels sprout-like heads emerging from the forgotten stump, your first cabbages of the year!
Make Leaf Mold
When raking up your leaves this fall, remember to save some to make leaf mold, a fantastic soil conditioner and organic mulch. The easiest way to do this is to build a cheap wire bin about three feet wide and high that will hold the leaves. Moisten them and check periodically to make sure they don’t dry out. You can also fill a few garbage bags, moisten the leaves with a hose, and cut slits in the sides. Put these bags behind the house or garage and forget about them until next spring. Either method will take 6-12 months, but you can decrease this time by chopping up the leaves with a lawnmower.
Compost or Trash?
As you harvest and remove warm-season crops, remember to completely clear away debris. Leaving old squash and tomato plants on your beds will increase the chances of disease and insects overwintering that may cause problems next year. Also, before tossing the dead plants into your compost pile, determine if they were affected by any kind of disease or pest. If there is any doubt, toss them in the trash or city yard waste dumpster. Most home compost piles don’t achieve the temperatures necessary to kill these effectively.
Water Cool Season Crops
After the heat and occasional drought-like conditions, we can forget in the fall that warm, sunny, days with comparatively low humidity also require us to be diligent about watering cool-season crops. Leafy greens and root crops like constant moisture (but still need to dry off at night). Emerging seedlings will benefit from frequent watering as well. Unlike fruiting summer crops, daily sprinklings will give you quicker yields than if you let the beds dry out for a few days. Make sure that the water still percolates a few inches into the soil for best results.
Nearly Time to Harvest Sweet Potatoes
If you planted sweet potato slips back in the spring or early summer, check for yellowing leaves. This will indicate that you might want to take a peek at the tubers underground to see if they’re big enough. However, waiting until just before frost may improve yields, taste, and vitamin content. Once the vines are blackened by frost, though, the tubers should be lifted immediately. Harvest during dry conditions using a digging fork in a wide circle around where the plants enter the ground. Dry in the sun and cure in a warm, airy environment (85⁰) to heal cuts and improve storage ability. Remember to save one or two for starting slips in the spring!
Last chance to plant seed crops in 2017!
This weekend may be the last chance to get a seed crop in the ground. Most cool-season vegetables will take two months to get good harvests, especially due to shorter day lengths and cooler temperatures. Vegetables with short harvest times (radish, lettuce, mustard greens) will be a good choice, as well as root crops (carrot and parsnip) that can be mulched or covered with a cold frame and protected from freezing weather. Spinach can also be sown, however, with some good protection this crop can overwinter and provide your first harvests before spring next year.
Hornworm in the Garden
The time is ripe to begin spotting this critter in your garden. The caterpillar’s distinctive green stripes and sheer size make it more noticeable than other pests you might find in your garden. Often causing defoliation and taking bites out of your tomatoes, the hornworm may not necessarily kill your plant, but it can create conditions ripe for sunscald. If you notice eggs on its body, a beneficial wasp has parasitized it, and is best left alone. Otherwise, pulling them off by hand or using a BTK product should limit the problem.
Last Chance to Plant Warm Season Crops!
With barely two months left of frost-free weather left this year, this week may be your last chance to plant a warm-season crop. Look for those in the 50-60 day range, such as pickling cucumbers, okra, bush beans, and summer squash. This may also give you some relief against damaging pests, such as the squash vine borer, which by mid-August should no longer be laying eggs in your tender plants. While you may not achieve yields like those in the summer months, it’s nice to be able to extend summer harvests into the fall.
Plant your Fall Garden
The heat broke and it is now not so difficult to think about fall gardening. Just in time because it is time to plant that fall garden. First, clear some space and prepare the soil by adding some compost. You may want to shade the soil with a piece of lattice or shade cloth to keep the soil cooler and moist while your fall plantings germinate and get established.
Sow early bush beans, beets, carrot, turnips, radishes, lettuce, and spinach now for fall harvest. Plant the seeds twice as deep as you would in the spring and keep the seed bed consistently moist until the seeds have germinated and the seedlings are established. Spinach will germinate more consistently if you refrigerate the seeds for several days before you sow it.
It is also time to transplant the brassica seedlings – the kale, broccoli, cabbage, and collards. The best time to transplant is in the late afternoon, avoiding the hottest part of the day and giving plants an opportunity recover from transplant shock without the stress of the midday sun. Watch the forecast and aim for a cooler and cloudy day. Soak the soil thoroughly and keep the soil moist until seedlings are established.
Gear up for Fall Gardening
While it may be hard to imagine, but it is time to start gearing up for fall gardening. It may be a disheartening as, due to the heat over the last two weeks, yields of your favorite summer crops may have slowed or even halted as the temperatures have climbed, as the plants go into survival mode and divert resources just to finding and moving water.
As long as you keep them alive and minimize the drought stress, the plants will start producing when the temperature drops into production range.
Along with the air, the soil has really warmed up and many cool season crops will not have great germination rates. In advance of sowing them, bring the soil temperature down by shading it with lattice propped up above the bed or using shade cloth over the low-hoop frames. You can plan ahead for next season and use a trellised summer crop to shade the soil. Stop by the Demonstration Garden to see an example.
When it is time to sow those cool season crops, plant them about twice the depth than you did in the spring. Then keep the seedbed moist until the seeds have germinated and are well established. For greens, that is about a week. For root crops, lettuce, and spinach it may be a bit longer. If you do not see germination in 10 days to 2 weeks, sow again.
After your seedlings are established or when you transplant seedlings you purchased or started indoors, add a healthy layer of compost or leaf mold, leaving a “moat” around the seedlings. If you’ve had weed issues, lay down a layer of newspaper first and then weigh it down with your mulch of choice. Keep an eye out for snails and slugs.
Heat Stress in the Garden
With the heat we’ve been experiencing the last several days, many of crops will experience blossom drop and not set fruit. The most notable is tomatoes but several other crops may not either. This will not affect the tomatoes or other fruits already forming but you may notice that you aren’t having any new tomatoes form and that blossoms are turning brown and dying.
The reason this happens is that the plants, responding to heat stress, don’t have the resources available to make new fruit. Above 94F, photosynthesis drops off and additional stressors like wind, drought, or high humidity can exacerbate the issue.
Do not panic. As long as the plant is kept healthy, production will resume once temperatures fall back into a more comfortable range.
Though there is very little to do that will get your plant producing when we are facing temperatures hovering near 100F, you can buy a few degrees of protection for days when ambient temperatures are in the low to mid-90s by keeping your plants well-watered to ward off drought stress. In addition, mulching the soil with compost will help keep the soil cooler and moist.
For next year, you may also want to consider incorporating a few more heat tolerant varieties that have been bred to produce in southern climates into your planting plan.
Make sure to protect yourself from the heat by keeping hydrated, wearing a hat, and tending to your garden beds early in the day before the heat sets in!
Blossom End Rot of Tomatoes
Tomatoes are starting set or soon will be depending on the variety and when you planted them. This is when the blossom end rot sets in, if it does, even though you will not see it until the tomato is fully formed and starting to ripen.
Blossom end rot is not a fungus, it is a structural deficiency caused by inadequate calcium when the tomato is forming. This structural deficiency may provide an entry point for other diseases but even without a fungus, the bottom will be sunken, water-soaked, and may be black or brown and leathery. Some varieties are more prone to it than others – elongated and pear-shaped sauce tomatoes are the most susceptible.
In some areas, blossom end rot occurs simply because the there is not enough calcium in the soil. That is highly unlikely to be the issue in St. Louis because our soil’s parent material is limestone, which is composed primarily of calcium carbonate (CaCO3). So, adding calcium, as you might assume, is unlikely to fix the problem.
What is the probably cause is uneven or excessive soil moisture making the abundant calcium unavailable to the plant. The solution is two-fold.
First, mulch the soil with 2-3 inches of compost. This evens out and maintains soil moisture as the mercury climbs. It also suppresses weeds and improves soil structure and health.
Second, check soil moisture before watering. Insert your finger 2″ deep into the soil. If it is moist, hold off another day or so. If it is dry or nearly dry, water deeply.
Another potential cause that the plant is growing too vigorously and the plant couldn’t keep up with its calcium uptake. This vigorous growth is caused by excessive nitrogen. If you are fertilizing your tomatoes, make sure that you are using an OMRI-certified fertilizer lower in nitrogen, lower the dose, and/or fertilize it less frequently. However, regular application of healthy compost, crop rotation, and planting cover crops to promote long-term soil health is preferable to regular fertilizing.
As the weather warms, we are seeing more evidence of pest activity in our vegetable gardens. One pest that becomes particularly active in June is the cucumber beetle. The adults, often seen flying around solo or hanging out just underneath the surface of leaves, have two distinctive patterns. The spotted one is often mistaken for the more beneficial ladybird beetle. Contribute to The Big Bug Hunt and report your sighting
Another way to spot the cucumber beetle is to find distinctive tears in many different kinds of leaves (not just cucumbers). While torn leaves are unsightly, the pests may also transmit bacterial wilt and other fatal diseases to your crops.
For control options, The Big Bug Hunt and High Mowing Seeds has some good options. Neem oil is another. Or, as many gardeners choose, plant plenty of cucumbers and harvest as much as you can before the beetle damage gets too bad.
Using Coffee Grounds in the Urban Garden
For those of you picking up coffee grounds from the local Starbucks or composting your own, a review of scientific data from Dr. Linda Chalker-Scott at Washington State University provides interesting insights into the commonly held beliefs and hopes of this supposed miracle garden amendment.
While the grounds don’t necessarily increase earthworm activity, the worms do pull the grounds into the soil, enhancing drainage and soil structure. pH is widely affected by coffee grounds, and it doesn’t necessarily make the soil more acidic (or less basic). Other amendments (elemental sulfur, peat moss, or pine needles) will work better.
Coffee grounds have been shown to curb some diseases such as Fusarium (a very difficult problem with tomatoes) and Pythium (causing damping off and root rot of seedlings and plants) in beans, cucumbers, spinach, and tomatoes. Using upwards of 20% grounds in a compost pile may show positive results.
Lastly, using grounds as a straight mulch is not recommended, as it can become compacted once wet. Apply in half-inch layers followed by thicker layers of coarse organic mulch. For more information, visit: https://puyallup.wsu.edu/wp-
Integrated Pest Management
As the weather warms, insect pests can easily wreak havoc on your vegetable garden, regardless of the time you put into protecting it. Dealing with them early will help you manage any potential problems.
One of the most important things to note about pests in the garden is that the presence of a pest species does not necessarily mean you have a pest problem. In a healthy garden environment, beneficial organisms will keep many pest species in check.
The first step before grabbing the spray bottle of unidentifiable liquid, try to identify pests to determine if they are harmful or helpful. Did you know that some wasps actually kill bad pests in your garden? The Missouri Botanical Garden and Texas A&M are good resources for figuring out what insects you have in your garden.
Then, if you’ve determined it is a pest and it is causing damage, we look to the Integrated Pest Management pyramid. First is culture and sanitation, then is physical intervention, next biological intervention, and finally chemical intervention. This Top 10 list from Organic Gardening magazine is a great place to start dealing with pests without reaching for a spray or dust.
If you’re seeing pest problems, it is a little late this season to address it with improving soil health, planting plants that attract beneficial insects, and other cultural interventions, though you can plan and possibly plant for later in the season or next year.
However, it is never too late to improve sanitation. Clear away weeds and any plant debris. Many pests are attracted rotting plant material or are harbored in weedy patches in or near gardens.
Among physical interventions are barriers, like collars to prevent squash vine borers from entering the stems, traps, and trap crops. If you go the barrier route, avoid covering the flowers of anything that requires pollination and avoid doing anything that might trap the pest in with your crop. Row covers are great for cole crops because they don’t require pollination… until you trap the infamous cabbage looper in with the cabbage or kale for it to munch away undisturbed.
The other physical intervention is manual removal. Head out of the garden early in the morning, while most pest are slower moving, locate the pest, pluck it off, and drop it in a bucket of soapy water. Or, for those pests that are small and fleet, vacuums are a possibility.
The next level is to introduce biological agents to disrupt the pests. This may be attracting or introducing predators or parasites.
As a last resort, is chemical intervention. For this, think about safe, organic pesticides to rid your plants of the problem pest. But a note of caution, organic is not synonymous with safe. Some organic pesticides are safer than others, so choose with care.
First, select one that targets only the pest you are dealing with. Johnny’s Seeds has a great chart to point you in the right direction. Always follow the instructions and apply the lowest effective dose. But first, consider whether the use of a pesticide is worth it. You may decide it is best to sacrifice the crop, pull it out and plant something else.
Recovering from Heavy Rains
With all of the rain we got last week, you may be in recovery mode this week… assuming that your garden wasn’t underwater last week. As always, it starts with paying attention to the soil. First and foremost, avoid working the soil until it dries out. St. Louis has heavy clay soil that clumps and compacts when wet.
Be on the look out for weeds. Many plants seem to have grown inches with all of the rain, including the ones that we don’t want. Luckily, with the wet soil, they will be easy to pull.
Add an inch or two of compost, leaving a moat around any plants you have planted. The soil may be depleted of nutrients and compacted after the heavy rain. Compost will help replenish nutrients and as earthworms and other invertebrates work the compost into the soil, it will improve soil structure.
Finally, turn the compost pile. It is too wet right now, which can lead to anaerobic decomposition. Anaerobic decomposition is smelly and may produce undesirable byproducts. Giving the pile a quick turn will reintroduce oxygen and help dry it out faster.
Plant Cucurbits – Now!
Do you have a gap in the garden… a spot to fill for for the summer? Now is the time to plant cucurbits – pumpkins, squash, melons, and cucumbers. They do well direct-seeded into small mounds. They also like a lot of organic material, though you won’t want them to, they will grow quite happily in the compost bin. So add a good amount of compost to the bed as your form the mounds.
Cucurbits fall into two categories, vining and bush. Vining cucurbits, typically cucumbers, melons, and some winter squash will happily be trained up a trellis, saving room and decreasing the incidence of disease and pest damage. The larger melons and pumpkins will need to sprawl due to the weight of their fruit.
The bush cucurbits, summer squash and some winter squash, need to sprawl and will need more horizontal space to grow than the trellised vining cucurbits.
Weed diligently but carefully when the plant first germinates, but over time the vines should shade out any additional weeds. Once a month or more during the growing season side-dress the plants with compost or rotted manure.
If you haven’t see many bees around, you may want to try hand pollinating to get better yields. Cucurbits are monoecious, meaning they have separate male and female flowers as oppose to perfect flowers that have both male and female parts. However, the male and female flowers are are on the same plant.
In order to hand pollinate, pick the male flowers. They emerge before the female flowers and have no ovary (bulb-like structure) at the base of the flower. Then carefully remove the petals to expose the stamen and use it to brush the pollen on the stigma in the female flower.
Water deeply during flowering and remove flowers at least one month prior to frost to focus energy on existing fruits.
The warm spring days may bring bolting in our spring crops like lettuce and spinach before we are ready. Bolting is when a plant produces flowers. It happens when the temperature climbs and daylight changes and turns the leaves bitter and unpalatable.
You can delay bolting by providing those plants, first by selecting “heat tolerant” varieties when planting. Second, you can shade your plants. Prop lattice above the lettuce to shade them and drape shade cloth over loop hoop frame.
At the Demonstration garden, we have built a lattice over which we will grow cucumbers to shade the soil below, making it a more hospitable space for those cool season crops.
Transplant “Tender” Plants
Finally…it’s the end of frost in St. Louis (or at least there’s about a 90% chance that we won’t have temperatures below 32 degrees anymore). It is still a gamble – though maybe less so than in previous years – to transplant “tender” plants outside (because of that 10% chance). However, for those of us who are impatient or want early harvests, now is the time to put warm-season crops in the garden.
For the next few weeks, check the weather forecast every day, and keep an eye on night time temperatures. If it looks like it might hover around the freezing point (especially with rain), take care to protect your tender crops with clothes, hot caps, cold frames, row covers, etc. By the first of May, we are usually in the clear for agreeable tender crop temperatures.
Citizen Science in the Garden
Gardeners are amateur scientist, observing and experimenting in the garden bed. Why not harness some of that observation for the greater good and participate in some Citizen Science?
The most obvious for the gardener is to participate in The Big Bug Hunt. With this project, you can sign up to receive alerts when pests start to appear in your area so you can take preventative measures to keep pests in check and prevent damage. In turn, you can also report sitings of pests to both help other gardeners and create a fuller picture of what is going on in the pest world.
While there are many others with citizen scientists with topics ranging from aging to zoology, some others relevant to gardeners are Project Bud Burst, a phenology project which tracks the timing of plant changes through the seasons. This is creating a fuller picture of how changes in climate are affecting plant life cycles.
The University of Illinois is conducting the The Bee Spotter project, which tracks and identifies bees spotting in Illinois, Missouri, and Iowa. This just requires you to photograph bees you see and submit them to their website.
A similar project that covers all of North America is Bumble Bee Watch, which is documenting the presence of the very important North American bumble bee population (great tomato pollinators!).
e-Butterfly is documenting butterfly populations in North American. As with The bee Spotter and Bumble Bee Water, you photograph and submit your photos to their website.
If you want to expand beyond pests, pollinators, and plants, iNaturalist, is program in which you can record and share observations of many different species.
Go forth and collect data!
Starting Melons, Cucumbers, and Squash
With less than two weeks left before our last average frost date (April 15), we are counting down the days until we can put those tender seeds and seedlings into the ground.
While a lot of the transplants you’ll be adding to your garden take several weeks of indoor growing before they are ready, cucurbits (melons, squash, and cucumbers) are ready to be set out fairly quickly. If you want to get a head start on harvests, sow these crops indoors over the next 2-3 weeks so they’ll be ready once our frost is likely over. Cucumbers should be sown now, as they only need about two weeks before transplanting. Melons also take as little as two weeks for transplanting, while squash will need about four. Sow these in the next week or so to be put in the ground a few weeks after the last frost.
Spring in Missouri is always unpredictable but the extra warm February warmed up the soil early, which can inhibit germination for some of our favorite spring crops like peas and spinach. There are a couple of strategies to work around the weather.
First, try succession planting. Planting some now and some in a week and maybe yet another week will increase your chances of finding the right weather window for your plants to get a established. Do watch the weather and avoid sowing seeds right before a cold rain is forecast. Imbibitional chilling injury or dousing a seed that is ready to germinate with cold water can also bring that process to a halt.
Second, if picking up some new seeds, look for “heat tolerant” varieties.
Third, consider shading the soil. You can use shade cloth over hoops for low hoop bed or lattice or trellis materials to accomplish this.
As you get ready to transplant seedlings out in your garden beds, remember to harden them off first. This will involve a 7-10 day process of acclimating seedlings to the outside world, gradually exposing them to more sunlight, cooler temperatures, and less watering.
Start by root-pruning seedlings in their trays or pots and decreasing watering times. Place seedlings in partial shade during the day, bringing them in at night for the first 3-4 days. Then begin to expose them to more direct sun and cooler temperatures. After 7-10 days, they should be out overnight. This process builds cutin in the leaves, a waxy layer that protects the plant from sunscald, dehydration, and disease.
Consequences of an Unseasonably Warm Spring
With the extended unseasonably warm weather we’ve been experiencing, we are going to face some additional challenges in the garden this spring. Soil temperatures are already quite warm, which means the planting calendar may lead you astray.
First, the bees are coming out far earlier than usual and they are coming out to fewer flowers. Though many trees are also blooming early, the drops in temperature we’re still experiencing can freeze the flower buds. There are three things you can do to help.
First, when thinking about planting this year, make sure to add additional native flowering plants. Plant some that flower in each season. If selecting plants from a nursery, make sure to avoid plants treated with neonicotinoid pesticides.
Second, add more shelter for bees around your garden that can be bee hotels, piling leaves up in a corner, or bundling the stalks of your perennials together in an out of the way place. Finally, mow your grass less frequently. Longer grass provides more sources of food for the bees and more cover for them to get from place to place. While these practices will not help the bees emerging now, increasing the flowering plants and other bee-friendly practices will be that much more important moving forward.
The other issue is that the soil may be too warm for some of our cool season crops to germinate well. You can shade the soil to bring the temperature down until your peas and spinach other crops have germinated. You will probably also want to look for “heat tolerant” varieties of your cool season crops, particularly those you want to direct seed.
Starting Seeds Indoors
Next week marks the six-week countdown until our last average frost date of April 15. That means if you haven’t yet started your tomatoes and peppers indoors, now is the perfect time. Tomatoes and peppers should typically be started indoors 6-8 weeks before the last frost date and transplanted about 1-2 weeks after the last frost date for best success.
Keep the rooting area of the seedlings warm, about 75⁰ for best germination rates. You can do this with a propagation mat or put it on top of the refrigerator or another warm spot. You can relocate once sprouted but do not move it to a chilly spot.
Seedlings will need additional light, a sunny window sill and the ambient light in the room will not be enough to grow stout, healthy plants. A full spectrum fluorescent light works well but it does need to be close to the plants, 1-2 inches will keep them from getting leggy.
Transfer them up into larger pots when they are 2-3 inches tall and have several sets of leaves. At this point, you’ll want to decrease watering to allow some drying to occur between watering. Also, take care to keep the foliage dry and help limit your chances of fungus and disease outbreaks. Directing a small fan on the seedlings on low will both strengthen the seedlings and help ward off fungal growth.
Early Spring Garden Clean-ups
With everything dead and dormant in the garden, now is the perfect time to check on your native and ornamental plantings. Look for damage to trunks and roots, as well as dead limbs. For many plants, now is the best time of year to prune, so take your pruning shears with you to cut back any problem spots.
If you left the stalks of your natives or perennial ornamentals in place over winter for visual interest or to create habitat and food for birds, now is a good time to cut that back. Getting the garden cleaned up now before new growth starts emerging makes spring garden maintenance a snap!
Early Spring Gardening Techniques
or those chomping at the bit, it is time to start the early crops. Aside from sowing some of those slower growing crops – like onions – indoors now, the other thing to consider is building or installing a cold frame or a low tunnel. These structures can be add a few weeks to your growing season on either end.
In the spring (or late winter), they will warm the soil and allow seeds to germinate sooner. They are also a great place to harden off seedlings you started indoors. They protect from the wind and temperature extremes and shield from the sun as it gets stronger.
A couple of notes of caution:
First, while we do not normally need to worry about water in the spring, anything in a low tunnel will need to be watered because it isn’t receiving any rainfall. However, the bed will not need as much as it will in the late spring and summer because you are losing far less to evaporation and transpiration. Similar consideration should be given with the cold frame though it is less likely to need additional water because the surrounding soil is often saturated.
Similar consideration should be given with the cold frame though it is less likely to need additional water because the surrounding soil is often saturated.
Second, both the cold frames and the low tunnels need to be vented when the temperatures climb. We’ve been known to have the 70°F day but even on a sunny 30 or 40 degree day, the temperatures in the cold frames and low tunnels can rise the point of damaging plants.
Growing the Garden in Winter
While community gardeners have some downtime in the winter, it is short-lived and now is the time to start gearing up for the next growing season.
First and foremost, community gardeners can use the winter to tend their community. Garden leaders can use the slower time after the holidays to get in touch with fellow gardeners and determine whether they will be returning this growing season.
This is also an opportunity to start recruiting new members or set up new roles within your garden. Maybe this is the year to increase on-site composting – create a compost team of people who commit to turning the compost on a weekly basis. Or maybe your garden is ready for a social committee that will organize potlucks and other community-building events.
This is also the time to look around the garden to determine what is missing or what needs to go. Are there ornamentals that will need to be divided or gaps to be filled? Are there hardscape materials like picnic tables or additional signage needed? Does the garden need some new tools? If so, consider Gateway Greenings annual expansion grant or keep your eye out for other funding and donation opportunities.
All gardeners can start thinking about their own plot. Gardening allows you to grow everything from the generic slicing tomato to an exotic vegetable that you have never tried. This is the time of year to let you imagination run wild and consider the options that growing your own food gives you.
Are their varieties of your favorites that you have never tried? Think about vegetables that you have had trouble with in the past. Is there a variety that is more resistant to the problems you have been having or is that an opportunity to try something completely different? Put your head together with your fellow gardeners, as you are only likely to use a few seeds of a packet or planting a handful of seedlings. Organize a seed or seedling swap and share the wealth just as you are kicking off the growing season.
Starting from Seed
Believe it or not, now is the time to gear up for spring planting if you are starting from seed. Several of the brassicas and leeks and onions are started indoors in mid-January, the remainder of the brassica family needs to be in the seedling tray in February.
While the seedling catalogs maybe coming in now, first, check out what you have left over from last year and check your garden notes – what grew well, what did you like. Do a germination test: put 10 seeds in a folded, damp paper towel, keep the paper towel warm and moist for about a week. If fewer than half sprout, order new seed.
Then, clean your seedling containers well. You can reuse old nursery trays, yogurt containers, or anything that is relatively small and that has drainage holes (you can add these!). However, you do want to clean them thoroughly to minimize the chance of seedlings suffering from damping off.
Eventually, your seedling will need light and some may need heat for germination. You may decide to invest in a shop light and you can buy grow bulbs. However, any cool spectrum light bulb will work work as long as it is close enough to the seedling tray.
You can provide heat by purchasing a propagation mat but putting the seedling tray on top of the refrigerator or other heat-producing appliance. Just be aware, the warmer the environment, the faster the tray will dry out and drying out means death for new seedlings. Once the seeds have germinated, the plants do not need the additional heat as long and can be moved to a place with better light and where it is easier to water.
If you still have carrots in the ground, you might want to leave them there to harvest throughout the winter! By using a good, deep layering of straw or leaf mulch (4-8″), you can keep the roots from freeing or heaving in the ground. It might help to mark their place with a stick or colored marker in case the green vegetation dies back during extreme cold.
As the carrots concentrate sugars to survive the winter, you might also find that their taste will improve, especially over those grown during the warmer months. Since they are a biennial, it will be important to pull them up before next spring – once they flower the root will become inedible!
Storing Vegetables During the Winter
The following link gives a good summary about storing vegetables in the home. An interesting technique to try with some stored vegetables during the winter is a technique called “forcing”. This is used primarily with root vegetables that are harvested from the garden just before the ground freezes. Cleaned roots (beets, turnips, celeriac, etc.) are planted in moist sand or compost and set on a window sill. From the stored energy in the roots, edible greens are produced that can accent a winter dish or be added to salads. This may also work with a harvested cabbage plant: pull the entire thing, roots and all, cut off the head, and plant in moist sand in the window. Harvest the greens as they sprout.
Something to be thankful for
This extend bout of warm weather has us a month behind on our first frost. Many of the chores to do around the garden this time of year are usually working with the overnight freezing temperatures and even with our first real frost across the region happening this weekend, the near term forecast doesn’t have overnight temperatures falling into the 20s on a consistent basis.
So, hold off on heavily mulching things like strawberries and root crops. Watch the forecast for when the ground is likely to freeze for mulching those root crops as those cold temperatures cause those root crops to sweeten. And give the strawberries a several nights in the 20s to ensure you aren’t harboring pests in the mulch.
And that is something to be thankful for – the warm fall weather has allowed us to draw out our gardening chores a little.
Making Leaf Mold
When raking up your leaves this fall, remember to save some to make leaf mold, a fantastic soil conditioner and organic mulch. The easiest way to do this is to build a cheap wire bin about three feet wide and high that will hold the leaves. Moisten them and check periodically to make sure they don’t dry out. You can also fill a few garbage bags, moisten the leaves with a hose, and cut slits in the sides. Put these bags behind the house or garage and forget about them until next spring. Either method will take 6-12 months, but you can decrease this time by chopping them up.
This time of fall is the best time to think about soil health. If you haven’t had your tested in a while or ever, now is a good time to do it. The University of Missouri provides this service and Gateway Greening is a drop off site. Here are instructions on how to do it.
With or without testing, you can do a few things now to improve soil quality for next year. Add any finished compost you have to your beds. It will improve your soil quality next year. If you use it as a mulch for beds where you do not have a cover crop, it will protect the soil.
If you’ve had a lot of pest issues, turning or tilling the soil once we get a freeze will expose the pests that live in the soil to freezing temperatures and reduce their numbers next year.
However, it is generally best to avoid too much digging or tilling in the garden. Tilling and turning disturbs soil structure built up over time with root grow, microbes, worms and other invertebrates, and regular addition of organic matter. With our heavy clay soil, it leads to clumping and hardpan. If you aren’t suffering from excessive pest problems, it is best to cover your soil with a natural mulch (compost, seedless straw, leaf mold) or cover crop and disturb it as little as possible
In late spring, when the garlic is almost ready for harvest, we frequently have people comment that they too would like to plant garlic… and now is the time to do it. Ideally, plant in the latter half of October but any time before the soil freezes (around New Year’s) will work.
Planting garlic is straight forward. Break apart your garlic bulbs, keeping the papery skin intact. Select the largest, best looking cloves. Plant pointed end up, 3-4 inches deep, 6 inches apart in rows that are 12 inches apart. Mulch heavily with compost or straw.
Mark your rows with something that will stick around through the winter and into the spring because garlic does not tolerate competition well. When spring comes, resist the temptation to interplant and make sure your garlic rows are free of weeds.
Planning for First Frost
Our first frost date – October 20th – is quickly approaching but that may be a little misleading. The first frost date is the date at which the likelihood of the temperatures falling below 32°F is 50% (whereas the last frost date is the date as which the likelihood drops below 10%). This year’s longterm forecast indicates that our first frost is still more than a month away.
So, our warm season crops may have a bit more time that we generally plan on. However, you are not going to see a great deal of production because production is mostly governed by the amount of daylight plants are receiving. As the days shorten, which we know to the minute, plants have less available energy to produce sugars not only to grow fruit (tomatoes, peppers, etc.) but also to grow leaves and roots and stems.
In addition, even though the warm season crops are not likely to be killed off by frost in the next week or so, many are at the end of their life cycles and others don’t tolerate temperatures below 50°F well. They won’t necessarily die but they aren’t thriving.
That being said, you can use this still warm temperature to get the last of those tomatoes ripened. The cooler temperatures assist in producing the red tomato pigments, lycopene and carotene, that we expect in ripened fruit. Plants loaded with green fruits will work against the ripening process, so remove the larger ones that have turned light green to white by clipping off at the stem and storing indoors at 55-70 degrees until ripe. Prune back vigorous plant growth to redirect energy into ripening fruits still on the vine.
Protecting plants from frost may keep the plant from dying, however unripe fruits can be injured at temperatures as high as 50 degrees. And if your plants have flowers but no fruit, it might be time to pull up the plant.
Remember to Water
With warm, sunny, and dry temperatures in the forecast, it will be important to water cool-season crops diligently. Leafy greens and root crops like constant moisture (but still need to dry off at night). Emerging seedlings will benefit from frequent watering as well. Unlike fruiting summer crops, daily sprinklings will give you quicker yields than if you let the beds dry out for a few days. Make sure that the water still percolates a few inches into the soil for best results.
Protecting Soil for the Winter
Fall is the time to think about soil health because healthy soil means healthy plants – plants that are more resistant to disease and pests and have higher yields. Healthy soils have the right balance of nutrients, have good texture, and a lot of healthy microbial activity.
The key to protecting and improving soil health is not leaving the soil exposed for an extended length of time, like over the winter. Leaving soil bare over the winter results in compacted soil, which makes it less hospitable to plant roots and all the other good things that live in the soil. The wind, rain, and snow also leach away important nutrients.
Now and in the coming month, there are some tasks you can do to protect your soil for the whole winter:
Add compost – 3 to 4 inches on top will provide a layer of protection for the soil, bolster the microbial communities in your soil, and add organic matter for the coming growing season. This will easily work into the soil as you plant next spring improving overall soil texture and condition.
Even better: plant a cover crop. You can seed your cover crop before you have removed the last of your fall crops so that they have a change to germinate.
The easiest is annual rye. It sprouts quickly and will die over the winter. It will add organic matter to the soil and even though it is dead, it will provide nice cover from the elements. Be careful when looking for rye seed those. There is also a winter rye, which is a perennial and will come back in the spring, and a cereal rye that will re-seed your garden bed if left too long. Make sure you select annual rye.
What you do not want to do is leave your annual vegetable crops in the beds to clean out in the spring. There are many pests and diseases that will thrive in this conditions. Next year, you will find that your problems start sooner and worse because those insects and microbes had a jump start.
Harvesting and Curing Sweet Potatoes
If you planted sweet potatoes, you may be anxious to start harvesting. While you can technically harvest as soon as the tubers reach a decent size, the longer they are in the soil the sweeter and higher in vitamin content they are.
Ideally, wait until frost kills (blackens) the vines and harvest immediately, otherwise they will begin rotting in the ground. If you aren’t sure you’ll be able to get to digging up those sweet potatoes right after the first frost (estimated October 15th though there is a possibility it could be as early as the first of October), wait as long as you can after the vine starts to yellow.
The other consideration is that it is far better to harvest sweet potatoes when the soil is dry, so keep an eye on the forecast. The sweet potatoes are much easier to effectively cure, which improves their taste and shelf life, if they aren’t coated in mud. Use a potato fork to loose the soil and lift the potatoes from the soil. The tubers can be a foot or more from the plant, so start some distance from the plant to prevent damaging the tubers.
While you can eat sweet potatoes straight from the ground, you are likely to be disappoint in them at least as sweet potatoes because they need to be cured. Curing triggers the sugar-producing enzymes and heals nicks. Skipping this step results in starchy, tasteless sweet potatoes with limited shelf life.
Curing is a two step process. First, leave the tubers in the sun for several hours to dry the skin in order to prevent rotting during the next step. Then move to a warm, humid place for 4-10 days. This is when the starch is converted to sugar. Ideal conditions for the first step are 85-90°F and 85% humidity. A hoop house usually provides optimal conditions but a pantry with a small bucket of water and space heater will achieve this (keep an eye on the temperature). The closer you get to these conditions, the faster the potatoes will cure but don’t despair if you cannot achieve them, just find the warmest spot you can, place the potatoes in newspaper lined boxes or crates, and give them a bit more time to cure, checking frequently for spoiling potatoes.
At the end of the curing process, place them in a cool spot. The second step’s ideal conditions are 55-60°F and 75% humidity. Basements frequently approximate these conditions
Reestablishing Monarch Habitats
If you have milkweed in your garden, this is the time of the year that you normally see monarch caterpillars on them. Unfortunately, there was a storm in early spring in Mexico that killed off many of the monarchs that overwinter in Mexico. This is the 2nd big storm in 5 years to hit the overwintering monarchs in addition to the loss of millions of acres of forest habitat to drought this year. They had a rebound year last year but this year you may notice fewer caterpillars and butterflies.
That makes reestablishing habitat along their migratory path that much more important. Milkweed is the only host plant for the monarch caterpillars and the adult butterflies need a nectar sources, which can be milkweed but are not limited to that. Planting a variety of natives supports those beneficial insects all year round but late-blooming natives in particular provide food sources for both butterflies and bees as they prepare for winter.
Now is a great time to think about planting some native perennials. They may look a little ragged this fall but the warm fall soil will encourage root growth. Just keep them well-watered this fall and next spring for a healthy, well-established plant next spring.
If you want to help with tracking the monarch as it makes it fall migration, you can contribute your sighting data to the Annaberg Foundations Journey North.
If you are looking to extend your fall harvest, now is the time to think about a cold frame. Cold frames are easy to construct from upcycled materials and you don’t have to have it ready to go right now but if you would like to have lettuce, spinach, or radishes that you are harvesting into the late fall and winter, you will want to plant them in the eventual footprint of the cold frame.
Keep in mind, that once we drop below 10 hours of sunlight per day, which happens on November 18th, plants go into dormancy and are not actively growing. You can still harvest but as the amount of sunlight decreases the slower the growth will be.
Herbs are some of the easiest and highest value thing to grow and now is the perfect time to capture that value for the winter months by preserving them. There are several ways to do this. Some are great candidates for drying, others are better if frozen whole, in water, or in oil. Making and freezing pesto is another alternative. And you can be creative with your pesto, thinking beyond the traditional basil & pine nuts. Or you can make herbed butter and herb infused oils and vinegars. Harvest your herbs when they are at their peak and put some up for the coming months. Then you can have a bit of summer in January by tossing some garden-grown herbs in a soup or bread.
Avoiding Blossom End Rot
Most of us have not seen the tomato crops that we would have liked — the heat in June set us back, with many suffering from blossom drop and poor pollination. Your vine may have finally been able to set some fruit during some of the breaks in the heat but you may now see the bottoms of the tomatoes looking damaged or rotten.
This is called blossom end rot. While it is called a rot and frequently mold spores taken advantage of an opening, it is actually a structural problem caused by a nutrient deficiency. The plants aren’t taking up enough calcium as the fruit forms. Some tomato varieties are more prone than other and it may happen on other crops as well.
Thanks to the prevalence of limestone (calcium carbonate and calcium-magnesium carbonate) in St. Louis area soils, rarely is the problem a lack of calcium in the soil. Most frequently, it is that the plant is not able to take up the calcium. Frequent fluctuations in soil moisture is the most common reason though root rot from overwatering and root scald from over-fertilizing can also be culprits.
The solution: add a thick layer (3-4″) of compost around your tomatoes and any other crop showing similar patterns – leaving a ring around the stem. Along with regular watering, this will keep the soil moisture more constant during the last weeks of summer heat and hopefully allow you a final wave of tomatoes before the frost and short days end our warm growing season.
The Dreaded Hornworm
August is typically when we begin seeing signs of tomato and tobacco hornworms. They are the grandest of our leaf-devouring caterpillars, and while kids will be amazed at the site of them, your tomato plants will not be happy. As they feed, the defoliation can eventually cause sunscald on the tomato fruits. They might also choose to take a bite or two out of the fruit. This series of pictures will give you a better understanding of all the life cycles of this fascinating, but frustrating pest, including pupa and adult.
As you scout, retain those hornworms that have become infested with parasitic wasp eggs. Leave those caterpillars be! Once the eggs hatch, the caterpillar will soon be down for the count and the resulting wasps will go after the more hornworms.
Last Chance for Warm Season Crops
While we are right on the cusp of fall gardening, we still have one last chance to squeeze in some quickly-maturing warm-season crops. We have about 2.5 months of frost-free weather left, so if we looking for crops that mature in the in the 50-60 day range, such as pickling cucumbers, okra, bush beans, and summer squash, we can fill in some gaps in our garden and get one last harvest in at the end of September and beginning of October.
This may also give you some relief against damaging pests, such as the squash vine borer, which by mid-August should no longer be laying eggs in your tender plants. While you may not achieve yields like those in the summer months, it’s nice to be able to extend summer harvests into the fall.
Time to Think About Cool Season Crops
Even though we are still facing weeks of heat, late July is a great time to think about your fall garden. There is less than three months of frost-free weather remaining. Pull out those seed packets from the spring to plant another round of cool-season crops.
Johnny’s Seed has a great fall planting calculator in which you put in the first frost date (Oct 20th) and it calculates when you need to plant those fall crops to have well-established before the days get too short and cool. Or you can simply add 14 days to the maturity on the seed packet. This is because the plants will grow more slowly than in the spring as they have successively less light with the shorter and shorter days.
One challenge to getting a start on your fall garden, particularly with the hot summer is that the soil is too hot to germinate seedlings. Try shading it with boards, burlap, or growing in the shadows of taller crops.
Good plants to try include lettuce, carrots, beets, turnips, spinach, kale, and collards. Water daily until germination and mulch to keep the roots cool during the heat of late summer.
Dealing with Summer
Summer time in St. Louis is always a roller coaster – this year, we’ve had a blistering hot June and July has started off wet. This is not great weather for many of our favorite vegetables, particularly tomatoes.
First, the heat and humidity can cause blossom drop. Then the sudden influx of moisture can cause cracking of the immature tomatoes that have formed. With rains of up to 2.5” in some parts of the St. Louis area, the drastic change in soil moisture levels from weeks of near drought could cause maturing tomatoes to grow too quickly, causing them to stretch out of their skin and cause noticeable cracks. The tomato will still be edible, those hoping to sell might find them less marketable.
Another more unsightly occurrence that happens in connection with excessive rainfall is blossom end rot. These sunken areas in fruiting crops may look like a disease, but are actually caused by a calcium deficiency. Often there is adequate calcium in the soil but it is unavailable to the plant when the soil is saturated.
The best solution to these problem is a good layer of organic mulch – 2-3″ of compost, straw, or leaf mold – around your plants. This improves the soils structure, making the moisture levels in the soil more constant over time – whether we have a deluge or drought. It also serves prevent splash back, which is when water hits the soil and splashes back onto the plant, carrying soil-borne pathogens with it. Finally, it can keep the soil a bit cooler, reducing heat stress.
What to do with Excess Harvest?
The summer crops are starting to come in! And if you’re lucky you may have a glut. Try an old school solution: pickle them!
Use this simple 24-hour refrigerator pickle recipe:
In a large pot, mix
5 cups water
1 cup white (5%) vinegar
1/3 cup pickling or Kosher salt
1/3 cup sugar (if desired)
1. Heat on high until the solution is clear (just before boiling).
2. Cut up freshly harvested veggies: peppers; cucumbers; beans; cauliflower; onions; garlic; and fresh dill.
3. Sterilize a self-sealing Mason-type jar in the dishwasher or in boiling water. Empty jar and stuff full with the veggies.
4. Pour the water/vinegar solution into the jar.
5. Wait until cool, seal tightly, and put in the fridge.
6. Wait at least 24 hours before eating.
7. Always store in the fridge when not using.
As you get a bit of experience, experiment with different combinations of veggies, herbs, and spices.
If the tops of your onions are beginning to fall down and turn brown, it is time to harvest. Stop watering the onions, and pick out a dry day to harvest.
Onions are one of the easiest crops to harvest; simply pull the onion by the neck out of the ground. At this point, it’s important not to wash off the dirt as you would most other crops. Gently brush off the crusted dirt and place all the onions in a harvest crate or wheelbarrow.
When finished, locate a good place for curing. This will be important if you plan to store your onions longer than a few days. The best curing place is an outdoor spot, preferably shaded and protected from rain and allowing good air movement. Old window screens allow air to move underneath the onions as well, hastening the process.
The curing is complete when they are dry and papery, not unlike the state you find them at the grocery store.
Last year, we were struggling with rainy and even cool temperatures. Last week, on the other hand, was a scorcher, so much so that 90°F temperatures seem like a respite… at least to us. Not enough of a respite for many of our favorite vegetable plants, unfortunately. You may notice many of your fruiting crops not setting fruit while temperatures are in the 90°s and above, especially with high humidity. Beans, peas, tomatoes, eggplants, peppers, melons, squash, cucumbers, and corn may all experience blossom drop when temperatures soar. As Deborah Kean at Oregon State University Extension explains, it can be a function of temperature alone but drought stress can also lead to plants failing to set fruit. While you can keep your plants watered to get them through the heat, there isn’t much to do about the temperatures other than wait for a break in the heat. Hot and humid weather will also decrease pollinator activity, causing deformed fruit or a lack thereof. One way to increase pollinating bees is to provide suitable habitat, since the majority of our native bees nest in the ground. This squash bee is an excellent pollinator of squash and pumpkins. Mulch your summer garden, but leave some ground exposed near these plants to increase their populations.
Protecting Our Pollinators
June is Pollinator Month! It is also the month with a lot of our most troublesome insect pests appear. How are those two related? Well, when those pests appear, our first inclination is to do something! And often that means reaching for a spray or dust to kill it.
Unfortunately, those insecticides can have unintended consequences – namely stressing if not outright killing beneficial insects, particularly pollinators. Bee counts are down and bee keepers report losing 44% of their honey bee colonies between April 2015 and April 2016.
Our pollinator species are in decline due to the loss of habitat and food sources and spreading of disease. As individual insects and as groups, their ability to withstand exposure to pesticides is greatly diminished. As pollinators are responsible for every third bite of food and nearly everything that we grow in the garden, that is also a problem for us.
What can the average person do?
1. Avoid using broad spectrum insecticides, even organic. Many people do not realize that the insecticide that they apply in one place – inside your home, the lawn, or that high-maintenance ornamental – can drift or travel to pollinator-attractive places. Without thinking, they apply and insecticide liberally to the lawn to kill a pest and then wonder why there are no bees in their vegetable garden. If it is meant to kill insects, it will kill the good and bad alike.
While it may be tempting to think “organic means safe,” this is not always the case. Even when applying more targeted insecticides, you should always apply them with caution and according the directions. Limit application to your problem spots, use the lowest effective dose, and select the one that degrades quickly. This is definitely not the time with “if a little is good a lot will be better.”
2. Know thine enemy. When you see damage, identify exactly what is causing the damage. Many interventions – both chemical and not – work well for some pests and make no difference for others.
3. Increase your tolerance of pest species. In a healthy ecosystem, there will be some pest species present. They are a food source for your beneficials. Pest species only become pests when the number threatens human health or crop yields. Don’t jump immediately to total eradication but plant enough to share and help keep those pest species populations in check by doing the number 4.
4. Use integrated pest management strategies. This means, first use good cultural practices when gardening that focus on creating a healthy ecosystem in your garden. This means you will likely have some pest species in your garden but they will be kept in check by beneficial organisms and not cause significant damage. If cultural practices are not enough, you may consider introducing or encouraging predator species to set up residence in your garden.
If that isn’t enough, the next step is to use your hands or hose or even vacuum to manually remove pests. Only after those have failed do you move on to chemical (still organic!) control. And you always have the option of deciding that the best course of action is to sacrifice the plant(s) under attack.
5. Plant native flowering plants around your garden. Aim for a good mix of early-, mid-, and late-season flowering plants. These offer many benefits.
First and foremost, they provide food and habitat for native pollinators. While exotics may be attractive, even when flowering they usually do not provide the same quality or quantity of food and habitat as their native counter parts. Many native pollinators require very specific native plants for certain parts of their life cycles like monarch butterflies require milkweed during their caterpillar phase.
Second, native plants are well-adapted to our soil and climate conditions and thus require less care, particularly once established. Then they thrive on neglect.
Third, thriving plants are far less vulnerable to pests and disease. Native plants are also adapted to our native pests and can withstand their assault.
Keeping a Close Eye
With so many potential problems that may arise with tomatoes, it’s a wonder why they are still the #1 crop in vegetable gardens. Maybe it’s just because they taste so good. If you set out your plants about a month ago, it’s a good idea to begin close inspection to find problems early. Two problems that are a real threat are Verticillium and Fusarium wilts.
These diseases are similar, both causes by fungi. Fusarium thrives in warmer conditions and is more prevalent the farther south you go. Verticillium likes cool, damp weather like the Pacific Northwest. St. Louis, of course, has a climate that accommodates both.
Both wilts typically begin on the lower or outer leaves and work upwards. With Fusarium, look for yellowing, wilted leaves and/or a wilting, sickly appearance on one side of the plant, caused by fungus clogging the water-transport mechanisms of the plant. Browning of the stem interior may also occur. Verticillium will create distinct V-shaped yellow patches on leaves, eventually turning them brown.
Gardeners using heirloom varieties should be particularly adamant about checking for these diseases, as they lack resistance. Choose varieties that show VF on the plant tags or seed packets if problems have occurred in the past.
All Solanaceous crops (tomato, pepper, eggplant, potato) are susceptible to these diseases, and there is no easy way to rid your soil once it’s there though solarization may reduce if not eliminate the prevalent. Always rotate these crops, 3-4 years if possible.
Immediately dispose of infected plants in the trash. Composting these will only spread the problem.
Composting can seem a bit daunting, particularly if you read a lot about it before you get started. But the best adage about compost is: Compost happens.
Short of placing your organic material in a sterile vacuum, it will eventually rot and turn into humus. Composting is managing that decomposition so that it happens as quickly as possibly with few of the… ahem… unpleasant aspects of decomposition (strong oder, pesky flies).
Many people are under the impression that there is only one right way of composting: hot and fast. Composting like this does retain more mass and nutrients and quickly converts the material that is most likely to attract pests. It also provides a steady stream of compost for your garden, a new batch in as little as every 6 weeks*. Hot composting also involves a lot of thermophilic bacteria, which heat up compost piles to 145°F or more, killing off many pathogens and weed seeds.
However, you have to work a bit for all of these benefits. Hot composting needs a good amount of material, requires regular management of the compost pile, and usually involves a workout. To get this process started, you need at least 1 cubic yard (3’x3’x3′) of material that is of a mixture of 3-4 parts browns/carbon and 1 part greens/nitrogen** layered like a cake. It also requires regular turning with a pitchfork to keep the pile well oxygenated and to move materials into the middle where they will also be subjected to the 145°F+ temperatures.
Cold composting means that it will take longer (a year or so) but basically requires little but making sure you have a good balance of greens and browns and that the greens are well-covered. You still get a great, free soil amendment – just somewhat less and a lot slower – and you are still diverting a lot of organic waste from the landfill.
To cold compost, you simply add material as you have it, covering kitchen waste and other green waste with a healthy layer of browns to keep the pests away and the smell down. Since a cold pile doesn’t heat up reliably, you do need to make sure that you are not adding diseased or infested plants or weed seeds. You can help the process along by turning or aerating it every once in a while.
With either method, if your bin/pile starts to smell, is attracting too many pests, or doesn’t seem to be composting, just do some simple troubleshooting. Usually the solution is as simple as turning it, adding some addition browns or greens, or wetting it down.
*Many methods promise much shorter turn around but 6 weeks is a reasonable estimate for an actively managed pile.
**You may come across widely varying ratios, from as little as 1:1 to as great at 30:1. This has to do with ambiguity about what constitutes a part – volume or mass.
The very detailed oriented may find it interesting to build a pile based on the actual mass of carbon (browns) and nitrogen (greens) of every kind of organic material added, and there are many charts that provide this information. This would be where the 25-30:1 ratios come from as all organic material is some mixture of carbon and nitrogen, but mostly carbon.
However, in the community garden, we don’t usually have the time, control, or inclination to manage pile-building that way. Thus, we are looking for a pile that has about 1″ of greens – green plant material, kitchen waste, overripe veggies – to 3-4″ of browns – dried plant material like dried leaves, straw, wood chips, shredded paper or cardboard. The browns tend to contain a lot more air and, if compressed, it would usually end up being similar in volume to the greens, hence the 1:1 ratio.
Gardeners are amateur scientist, observing and experimenting in the garden bed. Why not harness some of that observation for the greater good and participate in some Citizen Science?
The most obvious for the gardener is to participate in The Big Bug Hunt. With this project, you can sign up to receive alerts when pests start to appear in your area so you can take preventative measures to keep pests in check and prevent damage. In turn, you can also report sightings of pests to both help other gardeners and create a fuller picture of what is going on in the pest world.
While there are many others with citizen scientists with topics ranging from aging to zoology, some others relevant to gardeners are Project Bud Burst, a phenology project which tracks the timing of plant changes through the seasons. This is creating a fuller picture of how changes in climate are affecting plant life cycles.
The University of Illinois is conducting the The Bee Spotter project, which tracks and identifies bees spotted in Illinois, Missouri, and Iowa. This just requires you to photograph bees you see and submit them to their website.
A similar project that covers all of North America is Bumble Bee Watch, which is documenting the presence of the very important North American bumble bee population (great tomato pollinators!).
e-Butterfly is documenting butterfly populations in North American. As with The bee Spotter and Bumble Bee Water, you photograph and submit your photos to their website.
If you want to expand beyond pests, pollinators, and plants, iNaturalist, is a program in which you can record and share observations of many different species.
Go forth and collect data!
Direct Seeding Warm Season Crops
Do you have space opening up in the garden as you harvest some of those cool season vegetables? You can still direct seed some warm season crops to take advantage of that open space.
Beans mature in about 60 days, bush varieties tend to take a bit less, pole varieties a bit more. Bush varieties produce a big crop all at once and then taper off. They do not require anything more than water in a well-prepared garden bed. Pole beans produce over a longer period and do need something to climb – a trellis, teepee, or corn as in the three sister’s garden. Both varieties produce more when they are harvested regularly. Have some fun and plant some purple (though they turn green when cooked) or yellow beans.
The latter half of May and June is also the perfect time to plant okra. Okra prefers soil that is more acidic than St. Louis soil tends to be, so the more compost you can mix into your bed, the happier it will be. It may grow slowly until it really starts to heat up but when it does, it can get quit tall, so account for the potential shade it will cast when selecting your spot. Pods appear in about 60 days and should be harvested early – when they are between 2-4″ long – and often as that will spur more production. Once the pods get past 4″ they tend to get quite woody and are really only good for chicken feed though you could dry and harvest the seed as well. Okra can be quite prolific and okra freezes easily – you can put some in the freezer and pull it out for a nice gumbo in the winter – and pickled okra is a favorite!
Finally, most of cucurbit family – cucumbers, squash, melons – do just fine with a planting in late May and into June. The exception is the pumpkin, which needs the entire growing season to produce those sizable fruit. Just watch out for the adult squash vine borer in late June. If you’ve had problems in the past, stick to cucumbers, melons, and butternut squash as they are not usually attacked by borers or put a collar around the base of your vines to keep the vine borer from entering and killing the vine.
Ways to Extend Lettuce-Growing into Warmer Months
At Bell Garden, we have had some mammoth lettuce harvests thanks to the cool weather. Many of us are not sorry to see the end of lettuce season looming after weeks of salad 2-3 times per day! However, if you either haven’t experienced the glut or are such a lettuce lover that there is no such thing as too much salad, there are ways to extend lettuce-growing into warmer months.
First, select varieties that are labeled “slow bolting.” Gardeners frequently complain this claim is overstated but you stand a better chance with these varieties than a variety that has not been bred for that characteristic.
Bolting is a function of cumulative hours of sunlight – so there is a genetic timer that goes off after the lettuce has reached the total number of sunlight hours that induces bolting. However, some combination of heat and drought stress can shorten that time. Thus, the second thing to do is keep your lettuce well-watered particularly when the heat sets it.
The next thing to do is work with and not against any shady spots you may have in your garden. Those spots are best for growing things you want the leaf or root of rather than the things you want the fruit from and are perfect spots to get a few more weeks of lettuce to harvest.
If you do not have a shady spot, you can make shade. Trellis pole beans or something from the cucurbit family in such a way that it will cast shade on part of your bed and plant your lettuce there — the amount of shade will grow as the lettuce needs it.
If you do not trellis or you didn’t plan for it this season, you can also use shade cloth or lattice propped on something that gives your lettuce enough head room.
Of course, if the lettuce gets away from you, you can replant at the end of summer for a fall harvest and try again just spring.
With the Zika virus in the news, some may be wondering about controlling mosquito populations while still practicing water conservation in the garden, particularly with rain barrels. While there are currently no cases of locally-acquired Zika in Missouri, there are other mosquito-borne illnesses that are of concern, particularly West Nile virus. Even without these threats,minimizing breeding grounds for mosquitos helps to make our gardens and neighborhoods inviting places to be, the goal of any community garden.
Here are some strategies to employ to keep your garden mosquito-free(-ish) this summer:
Empty Water Collecting Containers
Mosquitoes need only a small amount of standing water to breed, so keeping an eye out for anywhere water can accumulate and stand for a week or more is the first step. The CDC recommends draining and scrubbing any water-holding containers like birdbaths and children’s pools once a week. Rain barrels that are primarily for stormwater diversion should be slowly drained after each rain event anyway so they can collect water during the next storm.
Many gardens use rain barrels as a water source for the garden and not primarily or at all for stormwater diversion. These barrels may not be drained on a weekly basis. In those cases, it is particularly important to follow the CDC recommendation of covering any opening with a mesh with holes smaller than an adult mosquito. Standard window screen should work.
Change the Surface of the Water
There are some additional measure you can take. Blue Water Baltimore offers several solutions including making the surface of the water inhospitable to mosquito eggs by adding a 1/4 cup vegetable oil or 1 Tbsp of dish soap. This treatment needs to be refreshed every time the barrel is emptied and after each rain event.
Another option is floating Mosquito Dunks® in containers of standing water. Dunks® contain Bti, Bacillus thuringiensis israelensis, a different subspecies of the the same bacteria you can use to control cabbage loopers and tomato hornworms. BTi is specific to mosquitos and other biting insect larva and are not thought to affect non-target species including caterpillars – good (e.g., monarch, swallowtail) or bad – or birds and mammals. This is a solution for any water container that you may have difficulty emptying on a weekly basis, but, ideally, it should be used sparingly to reduce the development of Bt resistance.
Thinning is a necessary evil in the garden when you direct sow, particularly when you have root crops. Some crops have compound seeds – each sprouting 3 or so seedlings. Some like carrots and lettuce have seeds so tiny that it is difficult to space accurately with out aids like pelleted seeds. Even with such aids, over-seeding, or placing seeds closer together than is ideal, is necessary to get a full crop, especially if you are using older seed.
If left to their own devices, overcrowded sprouts will compete for resources and struggle. They may fail to produce a crop or, at best, offer a meager specimen. So, thinning is a necessary part of gardening.
As difficult as it may be to rip (or trim) seedlings from the ground, all is not lost. If thinning is done periodically, you will have a steady supply of baby greens – baby lettuce, beet greens, radish, chard – to add to your salad mix. Some may stand transplanting, beets and chard notable examples. But be realistic about how much of either you really want. Committing to transplanting every thinned plant can quickly eat up all of your garden bed.
When possible, thin on cool, cloudy mornings and when the soil is moist. This will give the remaining plants the best chance at recovery because their roots are disturbed as well. Think about the size of the mature plant – particularly the size of the root for root crops – and thin so that the baby plants are about that far apart with a bit of a buffer. Or, if you are wanting to optimize your baby green production, thin so they are 1/2 that distance, just remember to return to get the other 1/2 thinned. After you thin, give your remaining plants a light watering to help them recover.
Some crops do fine with gentle pulling but others, particularly peas, beans, and cucurbits, may be too disturbed by this. Using a pair of garden snips or scissors to trim off the tops can result in cleaner baby greens and save your seedlings the stress of having their roots disturbed.
Okra is a fascinating crop, coming to America from Africa some 400 years ago. If your soil temperature has reached at least 60⁰, now is the time to plant this crop for an early summer harvest. Okra yields better when followed by a nitrogen-fixing crop such as beans or peas, so rotate accordingly. Soak the tough seeds overnight, or scratch with a file to quicken germination. Plant ½”-1” deep on the north side of beds (okra can easily reach 5’ tall). Being a heavy feeder of nitrogen, okra plants can use sidedressings of compost or manure tea during its growth. Once the beautiful flowers twirl up into pods, harvest small and often to avoid toughness. Wear gloves and sleeves, as the hairy spines are not pleasant on bare skin. Otherwise, plant spineless varieties such as ‘Clemson Spineless’ or ‘Emerald Spineless’.
Last Frost – but Beware
This is the week of the last frost! But beware — that magical last frost date is just when the probability of temperatures dropping below 32°F falls below 10%.
Even if it does not freeze, many warm season crops will suffer transplant shock and struggle in cool soil, so do not necessarily rush to move your plants out. Warms season seedlings, particularly if not well hardened off, can be set back 2 or 3 weeks by the rapid change in conditions (light, temperature, humidity) when they are moved from indoors to their spot in the garden. If the soil is too cool, you can lose the jump on the growing season you were hoping to get as the seedlings acclimate and the soil warms.
Consider the forecast and wait till those night time temperatures are reliably above 60°F before transplanting most warm season seedlings. Give your plants a few day to acclimate to being outside by hardening them off, especially if you’ve started your own seedlings indoors. Place them outside in a shady spot, protected from the wind. A cold frame with the top vented is ideal. Over the course of 2 to 4 days, move them into increasingly sunny and more exposed spots before planting.
Ideally, you would transplant on a cloudy morning and give your seedlings a thorough watering to help them recover from having their roots disturbed.
Sowing Summer Crops Indoors
It can seem to gardeners that the long winter months stretch with nothing really to do… and then many of us get caught flat footed at all of the things there are to do in the month of March! It seems we’ve just started planting our spring crops but with less than 2 weeks until our average last frost date (April 15) it is already time to move on to warm season crops.
Tomatoes, peppers, and eggplants, should have been started a couple of weeks ago or more for optimal planting. However, cucurbits (melons, squash, and cucumbers) are ready to be set out fairly quickly. If you want to get a head start on harvests, sow these crops indoors over the next week or so and they will be ready once the threat of frost is past over.
Cucumbers should be sown now, as they only need about two weeks before transplanting. Melons also take as little as two weeks for transplanting, while squash will need about four. Sow these in the next week or so to be put in the ground a few weeks after the last frost.Note of caution: Last frost date is the date after which there is a 10% or less chance of temperatures falling below 32°F. That is not the same as “no chance” as many of us found last year when we had a late frost last April. As that last frost date approaches, check the long-range forecast before transplanting tender vegetables. Also keep in mind, many of our warm season vegetables do not do well if planted in cool soil. Holding off another week or two allow the soil to warm will be better in the long run.
Onions: Good for More than Just Eating
There is a lot of questionable information and old wives tales circulating about companion planting. Some pairings work well in very specific circumstances and not in others and sometimes the science behind successful pairing is not well-documented. However, one of the tried-and-trues is planting onions among or around your other crops to deter pests – insects and rabbits. The strong sent of onions confuses pests by driving off some pest or by disguising the scent of other crop.
Even if you are not terribly interested in onions as a crop themselves, they are easy to grow interspersed with other crops. And they store well once harvested.
There are a couple of ways to grow onions – they can be started from seed indoors in late winter or direct sown outdoors in early spring. You can sometimes find seedlings to plant as well.
However, the easiest is onion sets, which is a year-old onion bulb grown from thickly sown seeds (the plants were not given enough room to grow full-size onions). These can be re-planted and with adequate space they will grow into full-size onions. Plant the sets with the point is just level with top of the soil about 3-4 inches apart (or vary depending on what you are planting next to). Like most root crops, onions like a soil that is consistently moist.
Onion sets are available at the Carriage House for $0.50/pound if you would like to give an onion boarder a try.
If you’re worried that the hot spring has limited your chances for planting cool-season crops, keep two things in mind while purchasing seeds and plants this year. First, look for vegetable varieties that are “bolt-resistant” or “heat tolerant”. This tells you that even during warmer-than-average weather, these plants will avoid flowering or bolting.
And second, according to Ross Penhallegon, horticulturist with the Oregon State University Extension Service, choosing transplants that are thinner than a pencil will give more defenses against bolting than those that are larger. Thicker ones may be induced to bolt after about of warm weather.
St. Patrick’s Day Planting
We generally use St. Patrick’s Day as our rule of thumb for when to plant potatoes. As with all rules of thumb, it is primarily used for ease of reference rather than its preciseness. There is a wide window of time in which you can plant potatoes in early spring but we associate potatoes with the Irish and so the week of St. Patrick’s Day it is.
However, rather than strictly adhering to the calendar, what you are looking for is friable soil, or soil that is about the texture of a moist cake that crumbles with you work it in your hands. As we’ve had an unusually warm winter, the soil is ready assuming it is not too wet from this past weekend’s rain.
Get certified seed potatoes from a good source (such as Gateway Greening) and cut them into 2 inch chunks that have at least two eyes on each of them. Ideally, you would cut them a day or so before you intend to plant, and place the chunks in a single layer, allowing the cuts to “heal” before planting. In addition, before you cut them, you can green sprout them or allow the eyes to develop more substantial shoot. Neither green sprouting or healing isn’t absolutely necessary but it can reduce the loss to rot, particularly if the soil is wet or cool.
To plant, you dig a trench in your bed and and plant chunks about 6” deep in good, friable, well-drained soil. Cover the hole or trench with a little less soil so the seed potato is covered by about 3-4” soil.
As the plants grow, pull soil from around the plant and hill around the base and developing tubers. This will allow better rooting and decrease sun exposure of the potatoes that will want to stick up from the soil. If you run short on soil, amend with compost as you go. Straw also makes an excellent hilling material.
You do want to make sure your potatoes are covered because potatoes exposed to the sun for too long, they develop chlorophyll – turning them green – and solanine. While the green from the chlorophyll is not a problem, it indicates that solanine is present and solanine is a toxic to us. If enough is ingested it can lead to an upset stomach. It is rare to eat enough to cause problems because it is bitter but in either case, allowing potatoes to green ruins the crop.
Once the plants bloom, you can steal a few “new” potatoes by carefully reaching into the hills and removing some tubers from the roots. Wait until the plant foliage dies back to dig out mature potatoes.
Dealing with Fall Cover Crop
Now is the time to get your garden in shape for this growing season.
First, if you planted cover crop last fall, you have a couple of options for removing it before you plant. You can tear it up and either use it as mulch in your bed or tear it up and compost it.
An alternative is to turn it into the soil. It will enrich the soil as it decomposes in place. However, that initial phase of decomposition binds up nitrogen in the soil and makes it unavailable to new seedlings so you will need to wait 2-4 weeks before planting depending on how well the cover crop is mixed into the soil.
Another caution about turning cover crops directly into the soil, you also risk compacting your garden soil. If that is your selected method, make sure the soil is fairly dry before starting.
Other tasks to accomplish: it is time to prune and cut perennials back. If you have fruit trees in your garden, you will want to prune them while they are still dormant – before the leaves start to grow! Cut back asparagus stalks and weed and cultivate the bed now.
Finally, rake out the leaves and other debris that have accumulated around garden. Cut up the woody pieces before adding them to your compost.
Given the mild winter and warm weather as of late, many gardeners have been itching to get started and now that we are in March, it is finally time. Counting back from our last frost date, we have 6 more weeks which puts us in prime planting time.
This week is the time to start sowing peas. In the next couple of weeks, add in most of the other cool season crops including beets, carrots, lettuce, mustard, kale, and collards.
If you do not see germination within 2-3 weeks, sow, sow again. If you refer to the Gateway Greening’s Planting Calendar, notice there are several weeks shaded for sowing crops. Seeds sown later, in slightly warmer soil, often catch up with early sowings.
Possibly more exciting than our cool season seedings is starting those warm season vegetables indoors. This is time to sow tomatoes, peppers, and eggplant indoors. You can make this as simple or as complicated as you’d like. There are seedling trays and special growing lights, whole kits that combine them all. Or you can reuse yogurt cups, egg cartons, and other repurposed containers and salvage a simple shop light. To start seeds all you need to do is provide the seeds and seedlings with a growing medium, water, and light… and possibly a little heat.
Many of our warm season crops have tropical (or subtropical) origins and the seeds need a little heat to germinate. Tomatoes, peppers, and eggplants’ preferred soil temperature is 75°F. You can invest in a propagation mat or place your seedling tray on top of or near a heat-producing appliance, like a refrigerator, to get them started. Just keep an eye on this because the dry winter air plus extra heat can quickly dry out the shallow trays of seedlings, killing them all.
Given our mild winter and May-like temperatures this weekend, it may have been tempting to get a jump on spring planting. If you did get seeds in the soil this weekend, be prepared for some less than spectacular germination rates after the (forecasted) rain and snow thanks to imbibitional chilling injury. This is a fancy way to say “my plants didn’t germinate properly because I sowed them right before a cold rain”.
Imbibition is the phase at which dry seeds absorb water to germinate. If the water is very cold, problems may occur. First, it is a good idea to check the temperature of the soil before sowing seeds. But if you lack a soil thermometer, check the forecast, and if the next three days show a good possibility of rain during cold temperatures or at night, wait to sow until the weather is drier.
Recent snows and chilly weather notwithstanding, we have had a mild winter in St. Louis, which may have you dreading a boom in this summer’s pest insect populations. However, you may not need to as it is “more complicated” than just simple temperatures as the University of Missouri Extension explains. The highlights:
Insects that winter above ground may have a higher survival rate based on temperature alone. However, less snow means that they are more vulnerable to the low temperatures as, somewhat counterintuitively, snow serves as insulation to below-freezing temperatures.
Insects that winter below ground are likely to be unaffected unless the frost depth is shallower than normal. In which case, more will survive.
The large fluctuations in temperatures – 60 or even 70 degree days followed by 20 degree days – can disrupt the normal rhythms that help insects survive cold temperatures. Namely, insects go dormant during the cold months and emerge when temperatures rise. If exposed to frigid temperatures when not fully dormant, damage or death can occur.
Even if they survive the temperature fluctuations, insects that emerge from dormancy too soon may starve as there is no food available for them.
The same forces working on pests are working on beneficial insects. So even if there is a larger-than-average pest population, there may be a corresponding larger-than-average predatory and parasite populations.
Taking all that into account, this underscores the importance of gardening-best practices that include minimizing the space for over-wintering pests by removing spent plant material from beds in addition to providing habitat and food sources for all stages of the life cycle for beneficials.
Given our mild winter, many are itching to get started in the garden. Luckily, there are a few things we can plant this month. It will work best if your soil is workable and friable but it is not necessary. You can simply poke holes in the soil and plant your seed. The vegetables below will germinate in soil as cool at 40°F, which usually means about 6 weeks before the last frost or about March 1st. However, this year, you can probably move that forward a couple of weeks.
Spinach is a common late winter plant that works great in cold weather. You can sow weekly from late February to the middle of April. Spinach needs regular moisture and likes cool weather. Harvesting spinach before the hot weather arrives will provide the best tasting leaves and limit the possibility of bolting.
Mâche, also known as corn salad or lambs lettuce, is a nice nutty flavored green. It is very cold hardy, tolerating snow cover just fine. It’s a slow germinator. While it can sprout in soil down to 41°F, building a small low tunnel might quicken your harvests. It does not tolerate warm weather, so if you want to try it, plant it early. Harvest with cut-and-come again, taking the outer leaves and leaving center leaves intact or do a one-time harvest and cut the plants off at the stem with a sharp garden knife.
Fava beans, unlike most beans, love the cold weather. Plant in late February to early March for a good harvest in May. Fava beans will not set pods once the weather warms.
Low Tunnels & Cold Frames
Get a jumpstart on spring planting by putting up a low tunnel or cold frame. Low tunnels and cold frames put up now will warm the soil several weeks early and allow your cool season vegetables to germinate. They will continue to protect seedlings from freezing temperatures and sun scald as we head out of winter and can also be used to harden off the seedlings started indoors.
Of course, you can put them back up in the fall to get a few more weeks out of those fall vegetables as well.
Low tunnels are simple to construct. Attach pipe straps – found in the plumbing section of the hardware store – to the outside of your bed. Bend small diameter PVC pipe (keep it warm until you are ready to bend it in place – cold PVC will snap!) and slide them into the pipe straps. Then cover with plastic sheeting. The heavier the plastic the better it will stand up to UV light and protect from cold temperatures. However, heavier plastic also lets less light in, which leads to slower growth. Greenhouse film is a plastic sheeting is designed to maximize light transmission and withstand the UV exposure and gives the best of both worlds but can be more difficult to find.
A cold frame can be constructed out of scrap lumber and an old window (avoid using windows with frames with lead paint). Construct a box from the lumber and add the winder to the top with hinges so you can vent the cold frame on bright, sunny days. Ideally, the window slopes and you position the frame so the slope is south-facing in order to get the most sun exposure. Add handles to the sides and you can use the cold frame to get a jump start on planting in your bed and then move it to harden off seedlings else where.
Even more simply, a cold frame from an old window and straw bales. Arrange the bale so the window rests on top. When the weather warms, remove the window and use the straw bales to mulch the garden.
Do remember that on bright, sunny days, even quite cold ones, temperatures inside cold frames and low tunnels can climb high enough to stress plants. They need to be vented during the day and sealed up as night approaches and temperatures drop.
This time of year, the birds and other small animals may have trouble finding food. Keeping them healthy and well-fed so they are ready to pounce on those insect in the spring can be a simple or involved as you’d like and the supplies are inexpensive, starting with bird seed from the hardware store.
If you don’t already have a bird feeder, a piece of plywood or cardboard provides a clear spot for to spread the seeds. Egg cartons are another easily repurposed container for birdseed though the cardboard may not last long in snowy and rainy conditions. Make sure they are hung or anchored so they don’t blow away when emptied. If you are feeling a bit more ambitious or want to involve children, there are many crafty projects. Some favorites are:
Toilet paper roll bird feeders – save those toilet paper rolls and cover them in peanut butter (or sunflower seed butter if those with peanut allergies) and then roll them in bird seed. Place the roll on a small branch. If you have pine cones, you can use them in place of the toilet paper rolls
Milk carton bird feeder – cut a hole in the side of the milk carton, decorate if you wish, provide a perch just below the hole, fill with bird seed and hang the carton outside.
Birdseed ornament – there are many recipes but here is one.
Garlands of popcorn, cranberries, Cheerios (birds are not that picky, so store brand will do just fine), stale bread, and chunks of fruit – thread them on string, twine, or fishing line string through branches.