Tag Archives: fall garden

Tips for Direct Sowing in Hot Weather

Lisa Dermer & Ira Wallace

Last week we finished harvesting our spring-planted cabbage and broccoli. Now it’s time to sow our first seedling bed for our fall brassicas: besides cabbage and broccoli, we’ll add cauliflower and Chinese cabbage. Later we’ll make sowings of fall carrots, beets, lettuce, rutabaga, turnips, and greens like spinach, chard, kale, and mustards.

Sowing outdoors during high heat can be tricky, but if you follow these tips you’ll find it’s worth the effort:

1. Sow in a closely-spaced nursery bed and transplant later. This lets you concentrate your efforts (keeping the soil moist and weed-free) on a small, more manageable area. (Don’t do this for crops that don’t transplant well, like carrots.)

2. Choose a location with afternoon shade. This will protect the sprouting seeds from drying out.

3. Sow under lightweight row cover or the newer temperature-neutral proteknet. Both protect from insect pests and help retain soil moisture.

4. Sow successions! Two weeks after your first sowing make another planting of the same varieties or other, earlier-maturing types.

5. Count backwards. Plan for cool-season crops to mature when cool weather hits, and use the days to maturity to plan when to sow.

6. Transplant and/or thin your plantings. Giving plants more space helps their roots access enough moisture. Young seedlings grow faster in hot weather, so plan for quick turn-arounds. Summer-sown brassicas may be ready to transplant in 4 weeks or less (they should have 3 true leaves).

Check out our Fall and Winter Quick Reference for more details about timing and what to plant for fall and winter harvest.

Order now if you haven’t already reserved your planting stock for garlic and perennial onions. Each order comes with a Garlic and Perennial Onion Growing Guide to get you started.

Summer Sowings: Continuous Harvests all Summer and into Fall

With summer’s intense heat in full swing, it can be hard to remember to sow cool season crops, but some fall crops need to be started as early as June, and many need to be started in July.

On our farm in central Virginia our average first fall frost falls in late October, but even where frosts come later or not at all you should start fall crops during the summer. Later plantings will struggle with fall’s low light levels, and won’t produce before growth slows to a near standstill in early winter (the “Persephone Days,” November 21-January 21).

To make sense of all the seeds we’re sowing during the summer months, I divide our summer plantings into three types:

1. Warm-season, slow growing summer successions: these are the bonus crops that many gardeners forget. A second round of tomatoes, summer squash, sweet corn, or cucumbers can keep you harvesting all summer long without interruption.

2. Fast growing summer successions: these crops require frequent, regular sowing all through summer. Because we’re sowing so often, these can be easier to remember. We sow beans, carrots, salad greens, beets, and radish seeds weekly. Be ready to baby your summer sowings: we water daily to keep them from drying out before sprouting. Lettuce needs the soil temperature to be below 80 degrees F, so you may need to sow in flats indoors, or even in the refrigerator, or sow in the evening and cool the soil with crushed ice.

3. Cool season, slow growing crops for fall harvest. We sow the Brassicas first: Brussels sprouts in June, and then broccoli, cabbage, and cauliflower in July. By mid-July we’re sowing fall greens: collards, Swiss chard, leaf beet, and kale, plus winter radishes. We sow Chinese cabbage in late July. Sow thickly in nursery beds and keep up with your watering; we protect these young plants from summer’s insects with spun polyester row cover or the new more durable and temperature neutral “proteknet.”

For further resources on planning your summer sowings, check out: Brett Grohsgal’s article Simple Winter Gardening, our article on Summer Succession Plantings, and our Fall and Winter Planting Guide.

Successions can be overwhelming, so we have some tricks that help extend harvests with fewer plantings:

1. Plant indeterminate varieties of tomatoes and cucumbers, and pole-type beans and peas. We still find we need a late tomato planting, because our earliest plantings taper down toward the end of summer (and our Heritage Harvest Festival at Monticello needs lots of tomatoes for the Tasting Tent).

2. Select heirlooms bred to provide extended harvests: many modern farms want concentrated harvests that can be harvested with one or two passes; but for more traditional growers an extended harvest was the ideal way to manage the bounty. Look for roots that hold well in the ground. Lutz beets are one of our favorites: they can be spring planted and will hold all summer without turning woody. However, they will be very large, so this only works if you’re happy cooking with multi-pound beets (try slicing cross-wise for beet burgers). Open-pollinated broccoli provides extended side-shoot harvests. Choose bolt-resistant greens and harvest by the leaf before before taking whole plants.

3. Choose seasonally appropriate salad greens: we want salads all year-round, but this can be tricky both when it’s hot and when it’s cold! Mustards and brassicas are more mild in cold weather, so get adventurous by adding young kale and tatsoi to winter and early spring salads. Choose cold-tolerant lettuce: red varieties tend to hold up better in frost. For hot weather, choose fast-growing summer crisphead lettuce like Sierra, or heat-ready greens like Red Malabar spinach or Golden purslane.

4. Set up a root cellar or similar storage system. Ultimately, some of your crops will ripen all at once, or you’ll be faced with a glut of produce when frosts threaten. Be prepared: have a proper storage area ready to go for your carrots, parsnips, turnips, cabbages, winter squash, and more. Be ready to finish ripening the last fresh tomatoes indoors. For fresh produce through till spring, we need good systems for storing and slowly working through the harvest. Nancy Bubel’s Root Cellaring is an invaluable resource if you’re looking to improve your winter storage system, and has lots of low-cost and little-time options, if you haven’t blocked off your whole summer to dig a cellar.

Planning and Planting for an Abundant Fall and Winter Harvest

article by Ira Wallace, with Lisa Dermer, photo by Irena Hollowell

Who wouldn’t want a fall garden abundantly producing cabbages, broccoli, carrots, turnips, parsnips, radishes, bok choi, Brussels sprouts, a wide variety of greens, and even peas? The trick to growing a cool season garden, and setting up the fall garden to continue through winter, is planning and preparation.

Check your understanding of cool-season. When grown for fall, many “cool-season” plants actually need to be sown and transplanted in high summer heat, and some as early as June.

Make room! We start our winter crops in August and September, and those plantings will need to supply us through February! We need lots of space for these plantings, so planning ahead is critical.

Below are our tips for getting the most out of your fall garden.

Choosing the Best Fall Crops for Your Garden

Look for storage varieties: these varieties have been bred to be grown in the fall and harvested for winter storage, or left in the ground to be harvested during thaws. Storage tomatoes can be harvested green to ripen slowly wrapped in newspaper in cardboard boxes; storage beets and radishes grow very large and keep well in the ground or root cellar.

Of course, be sure to choose the crops that you and your family enjoy and that are well-suited to your climate!

Calculating Time to Plant or Sow

Calculate back from your average first fall frost date to determine when to plant fall crops. Add 14 days to the listed days to maturity for your variety to account for the “fall effect” of shortening days and cooler temperatures. For plants with a long harvest period, like a broccoli that will make side shoots for 3 weeks after the central crown is gone, add that time in as well. (This may be as long as a month or more.) Add an additional 14 to 28 days if you will be starting transplants from seed, to account for transplant shock and setback.

For us, this means sowing most broccoli and cabbage in late June, with a second sowing 2 weeks later and often a third that we plan to keep growing under row cover until Thanksgiving or later if the weather is with us.

Sowing seedlings in pots or flats for transplanting out later lets you start your fall garden before space is available in your outdoor garden. Use benches or tables high enough off the ground (at least 3 feet) to deter flea beetles or use an enclosed shade structure.

We sow our fall crops in outdoor seedling beds well-supplied with compost in a location shaded from the harsh afternoon sun. The north side of a stand of corn, caged tomatoes or pole bean trellis makes an excellent choice. Outdoor seedling beds should be covered with thin spun polyester row cover or the newer Protek net row cover to guard against flea beetles and other insects. Summer broccoli and cabbage seedlings are ready to transplant in 4 weeks during the summer. Lettuce and Oriental greens in 2-3 weeks.

Making Space in your Summer Garden

Come summer, it can be tempting to fill every inch of the garden with summer tomatoes, peppers, squash, melons, and more. But even the most densely planted garden will still afford room to plant fall crops. Summer lettuce, green beans, radishes, greens, and root vegetables all yield space by late summer for the fall garden. Beds that were once filled with spring cool-season crops, like peas and fava beans, often rotate best into fall cool-season crops (if they’re not used for late summer successions). Plan for summer cover crops to be ready to turn under in time for fall crops.

When will each spring and early summer crop be finished harvest? You can calculate using the listed days to maturity, but we find that a mid-point check allows us to adjust for weather, later-than-planned planting, early bolting, or unexpectedly extended harvests.

Preparing the Ground for Fall Crops

Caring for the soil is even more important when growing 2 or 3 crops a year in the same area. Generously add compost and any other needed amendments before planting your fall crops. Keep plants growing fast and reduce risk of disease by providing regular and adequate moisture (at least 1 inch each week).

Season Extension

If you’ll be planting in cold frames, under row cover, or in a greenhouse, you can adjust your average last frost date backwards by two weeks or longer when calculating when to plant fall crops.