Summer is moving past its peak and the summer garden is winding down. The corn is harvested, late beans are coming in, and the last of the melons are waiting to be picked. Many people are tired of planting, weeding, and harvesting by now and are ready to think of quitting the garden soon for the winter. But not you! That’s because you enjoy cool season vegetables and want to feed your family from your land for more months of the year. You’ve kept your garden covered with plants, straw, or grass clippings eliminating much of your weeding. And you’ve planned your garden spaces to allow for cold hardy vegetables to go in as soon as summer ones quit producing. How you prepare for winter gardening is important, and which seeds you plant matters as well. Freshen up beds with well-aged compost before putting in the cool season vegetables so that they have nutrients to draw from.
There are three ways of approaching cold season planting: direct seeding, starting your own seedlings, or purchasing transplants. The problem with buying your seedlings is that your choices are very limited. So we’re going to limit today’s conversation to seeding directly in the soil and starting your own seedlings. With both approaches you’ll be able to select exactly which varieties you want to grow.
Certain vegetables simply grow better when sown directly where you want them rather than transplanting them. Many greens and anything that matures in the soil fit this category. So plan late summer/early fall spaces for winter radishes, beets, turnips, rutabaga, kohlrabi, lettuce, kale, spinach, mache, and tatsoi. Hopefully you’ve set up a lighted growing area in your home by now and are ready to start your seeds indoors. A sunny window can work as well, and it’s warm enough outside that you can start seed trays outside if you follow a few precautions. You don’t want the temperature to drop below 60 so bring the trays in if the nighttime temps will be lower than that. Seed starting trays are usually covered with transparent covers to retain moisture, but they’ll also bring the heat up drastically if left in bright sunshine. So keep your outdoor starter trays in a lightly shaded, yet warm area. I start mine on a large light table that my husband built in an unused alcove of our house.
You’ll want to start all cabbages, broccoli, and cauliflower in seed trays. These are large vegetables and the seedlings take up much more room than some of the root crops or smaller greens. I like to wait to dedicate space to the winter crops until I must put them in the ground because this allows me more successions of the summer crops before cool weather. Regardless, these larger vegetables do need to be transplanted by mid-August at the latest in our zone 6b garden or they may not come to maturity before an early killing frost.
The varieties that work well for us to take harvest out into fall and winter are:
- Arcadia broccoli which can take temperatures down to 25
- Monflor broccoli is a 1-cut type that handles cold well
- Purple of Sicily, and Song Cauliflower – harvest the heads before 30 degree weather
- Rubicon Napa cabbage must be harvested before it is 25 degrees out
- Deadon, Autumn Jewel, Brunswick, and Ruby Perfection cabbage can be harvested down to 19 degrees if it is only that cold for a few hours at a time. Very small heads survived multiple nights down to 15 degrees this past winter.
- Turnips, rutabaga, winter radishes, and beets need to be harvested before a hard freeze of 20-24 degrees regardless of variety.
- Beas kohlrabi can take temperatures down to 15 degrees if only for a short time
- Rainbow Swiss Chard easily takes sustained temperatures down to 15 degrees
- Red, and White, Russian Kale survive down to 10 degrees in our garden, as does any variety of spinach
Lettuces at maturity die around 25 degrees, but seedlings under 6 inches do well down to 10-15 degrees. The cold hardy varieties we plant for winter are Rouge Grenobloise, Winter Density, Marvel of Four Seasons, Landis Winter, Merlot, and Black-Seeded Simpson. We plant lettuce directly in place late August through mid-September to be harvested before Christmas. In October we start planting lettuce that we hope will overwinter at a small size to grow quickly in March. When the winter is warmer than usual, we harvest them in January instead. This past year we began winter-sowing lettuces in late-December as well for an early spring harvest. The seeds just sit there until weather conditions warm the soil to 35 degrees for them to germinate.
If you grow your own onions and garlic these are excellent choices for the winter garden. We start our onions inside from seed and plant them out in early October with straw packed tightly round the seedlings. We’ve overwintered Walla Walla, Candy, and Expression onions this way for an extra early summer harvest of large bulbs. Garlic bulbs should be planted around the end of October or early November in our zone. We plant them so the tips of the bulbs are 3 inches below the soil then cover them with 6 inches of fluffed straw. When the spring temperatures warm, the garlic plants push their way through the straw to grow tall and well supported.
If you haven’t planned for a winter garden this year it’s not too late. Order some cold hardy varieties of your favorite cool season vegetables. Whenever you pull a summer crop, replace it with seeds or seedlings for fall and winter plants. Even if you aren’t set up to start your own seedlings, you can experiment with whatever seedlings you can find at nurseries this fall. Just remember to surround your growing seedlings with straw as the weather turns colder. This will keep the soil at their roots warmer and help them survive colder temperatures than you’d thought possible.
Let me know how your fall and winter garden grows!