Second Harvest

Your second harvest: Start now, and you can double your yield this year and enjoy homegrown flavor into fall and winter.

November 26, 2010

Your vegetable garden is most likely at its peak of production right about now, with basketloads of summer favorites ripening every day. In just a few short weeks, though, the season for tomatoes, cucumbers, and other warm-weather crops ends. Good news: You don't have to wait until next spring to harvest more fresh vegetables from your garden. This week, you can plant a variety of crops that thrive in the cool temperatures of fall and some that even tolerate winter temperatures in the North.

There are many benefits to enjoy when you extend your growing season past summer. Most of the common, warm-weather pests and diseases either slow down or disappear completely when the weather turns cooler, making growing organically even easier. Fall and winter gardening is also good for your soil. Many organic gardeners are familiar with the cover crops that protect and build the soil. Fall and winter vegetables offer the same level of protection and, with careful management, do not deplete your soil. Best of all, crops such as carrots and kale taste better after they have endured some cold weather. If you've never gardened in fall before or even if you're an old hand at it, this guide is full of hints and tricks that make it easy and satisfying.

How Cold?
If you've gardened only in the summer, your first thought might be that your area is too cold even to consider fall and winter production. It doesn't get much colder than Maine, where grower Robin Follette harvests kale, cabbage, chard, arugula, endive, spinach, mache, carrots, turnips, rutabagas, and broccoli well into November with little or no protection. These crops are able to withstand a fair amount of cold and frost.

"Since learning to grow two months longer than usual for this area, I've stopped canning and freezing so many vegetables. We're eating fresh instead," Follette says, adding, "I pull carrots, beets, and turnips and dig potatoes until just before the ground freezes. I start pulling carrots when they're small but enjoy late carrots more because they're sweeter after the ground gets cold."

Frost in mid-September does not deter Ann Caffey, an OG test gardener, from growing vegetables in her Zone 4 garden tucked into the foothills of the Rockies in southern Colorado. Her secret for growing success in this high desert environment is what she calls the "waffle design." In September, she plants broccoli, chard, cabbage, arugula, and other cold-weather crops in sunken areas that resemble a waffle, creating a protected microclimate that is also enhanced by fencing. Because deep watering is better than frequent shallow applications, Caffey practices flood irrigation, watering up to 2 inches twice a week and using layers of straw to hold in moisture. Come October, she stops watering, and she keeps on harvesting right through the snow.

Three-Season Growing
If you're fortunate enough to live in USDA Plant Hardiness Zones 6 through 9, you can often extend your harvest through the winter and into spring. In Charlotte, North Carolina, the climate is mild enough for gardeners to brag that they have three growing seasons for vegetables. OG test gardener Don Boekelheide, in Zone 8, ushers transplants from late summer into fall by shielding them from the sun with floating row covers, "allowing them to grow to sweet maturity in the chilly months." Another protective cover he favors is Tufbell, which minimizes frost damage on lettuce and greens. Boekelheide believes in thinking ecologically--that is, making use of season-extending microclimates. A south-facing wall at his community garden holds the heat so well the gardeners harvest greens all winter.


When to Plant

Timing is the most important factor for success in fall gardening. Plants need to reach a good size before daylight diminishes to the point where they stop growing rapidly. While the days are becoming shorter in late summer, the soil holds more warmth than in spring, encouraging faster growth. By October, plants are not growing much anymore, particularly in the far North, where the days are very short. This means starting transplants from seed about the end of July.

If you have a local nursery that serves serious gardeners, you may find seeds and even transplants for sale in August and into September. This is the easiest way to start your fall garden. But if you don't have a nursery you can rely on, plan ahead by stocking up on the seeds you'll need when you buy your spring supply. Choice of varieties is important. No matter where you live, frost- or cold-hardy varieties are your best picks for the chilly temperatures of fall and winter (see "Fall Favorites," opposite).

Where to Plant
Where do you find room to plant seeds when your vegetable beds are in full midsummer production? First, look where early-season vegetables are winding down. Peas are a perfect example, or perhaps your early lettuce crop. If that's not an option, try establishing a small nursery bed just for starting transplants, which can be as small as a square foot or two. Or, you can raise seedlings in flats on your deck or any other level surface until they are ready to set into the garden.

Sowing seeds in midsummer is different from spring growing. To succeed where summers are hot and dry, sow your seeds in a cooler, shadier spot until they have sprouted and are ready to thin. At this point, the days are shorter and you can move them to a more open location. Remember, seedlings must be kept consistently moist to survive, especially in hot weather. Avoid spots with poor drainage, however; plants drown in spots that stay soggy all winter.

What to Grow
Cool cole crops. Kale (really delicious after it's exposed to frost) is a dependable crop anywhere. Many varieties are reliably hardy down to zero or even below with a good snow cover. Collards are equally hardy. In milder areas (Zones 7 and 8), broccoli lasts through winter with the added bonus of no cabbageworms. It comes back to life as soon as the days start getting longer. Try one of the sprouting broccolis, which are bred to be started in the fall for early spring production.

Tough greens. Endive, escarole, radicchio, spinach, and many Asian greens stand up well to cold. These include a whole range of mustards, mizuna, and shungiku (edible chrysanthemum greens). Chard often survives winter freezes well. Lettuce and parsley take quite a bit of frost and, when covered with snow, often last to spring. Spinach planted in fall produces some tender leaves before winter shuts it down. Mulch it well, and it starts growing again when temperatures warm up in spring.

Deep roots. Leeks, carrots, parsnips, beets, and other root crops are protected from the cold by the soil they are growing in. You can sow a second crop of most of these in midsummer or leave some of your spring-grown crop in place, using the garden as a storeroom and harvesting through the winter. Covering the plants with about 8 inches of straw or other loose mulch when hard freezes arrive protects the roots and makes them easier to dig up when the ground is solid.

Growing Guide
Crops for fall and winter production have the same needs as spring and summer vegetables: good drainage and fertile organic soil. But because the essential microbes in your soil are less active when the earth is cold, add compost or other organic material as well as organic fertilizer whenever you plant vegetables for a second harvest. It is especially important to renew soil that has just produced another crop. And practice patience. Shorter days and cooler nights slow down growing, adding time to the maturing process.

The most dependable way to extend your season is to set up a tunnel made from plastic tubing bent over into hoops covered with a sheet of clear plastic. This offers more protection than floating row covers and is most useful for really cold-hardy greens such as kale, chard, or mustard greens. Don't seal it too tightly; the sun can fry your plants even in midwinter.

If you have no plastic tunnel set up and no snow cover, protect your plants from a hard freeze by throwing a tarp over the bed temporarily. This also works during occasional ice storms.

Keep a lookout for plants that have been heaved by freeze/thaw cycles and settle them back into the ground.

You already understand the satisfaction that comes from growing and eating your own vegetables. Double that thrill when you harvest even a few vegetables in the cold and dark of fall and winter. Now that's a gardening challenge worth taking on.