Winter Gardening

Winter is the optimal time to eat many greens and root vegetables, when they are mild and sweet. Growing vegetables over the winter gives a head start on spring harvest so that you can start picking broccoli and other spring vegetables months earlier in the season. We have built a high tunnel many times only to have snowstorms, hurricanes, and other weather events take it down nearly every year. We eventually gave up on the high tunnel and have used low tunnels ever since. Low tunnels work great and never fail if you build them right. They keep the plants just as warm as high tunnels. I build my low tunnels out of wire hoops, the thickest frost blanket row cover I can find (I buy from Greenhouse Megastore), and add additional layers of row cover or even greenhouse plastic if temperatures fall below 20F. I grow my lettuce in a wooden cold frame entirely covered in frost blanket (and greenhouse plastic below 20F) for daily harvest all winter. I plant my vegetables in double or triple rows, about six inches apart, to fit two or three rows under a single low tunnel.

To harvest all winter, most crops need to be grown before first frost, so you have to plan far in advance. The vegetables will continue to grow all winter, but growth rates will be slower than that we’re used to in the regular growing season because of cold temperatures and reduced day length. Some vegetables, such as beets and carrots, need to be close to mature size by frost. Other vegetables, such as spinach, kale, and collards, should be grown for long enough that there is plenty ready to harvest by first frost, but they will slowly grow all winter. Think of overwintering more as keeping your ready-to-eat food in cold storage rather than as a rapidly-growing, quickly regenerating vegetable patch. You will need more linear feet of each vegetable for regular winter picking than you would for summer picking. For example, my spring and summer successive plantings of lettuce are about 25 linear feet per planting, but in winter I plant 110 linear feet of lettuce so that there’s enough to pick regularly all winter. You can squeeze in more linear feet by doubling and tripling rows so that the entire area under your row cover is filled with vegetables not open ground space. The planning and effort will pay dividends all winter because you’ll have reliable food year round, the flavors are superb, and the food stays very fresh.

Parsnips—I start parsnips in spring for harvest in the fall, winter, and early in the following spring. They are notoriously difficult to sprout. Some things you can try are watering every day or even twice a day, putting a board on top of the row until they sprout and then taking it off, chitting, or soaking in a variety of potions. Keep them well-weeded for the growing season. Before first frost, put metal wire hoops on and one layer of row cover.

Carrots—I start in early summer for harvest in the fall, winter, and early in the following spring. Keep them well-weeded for the growing season. Before first frost, put metal wire hoops on and one layer of row cover.

Beets—start in late June or July for harvest in the fall, winter, and early in the following spring. Keep them well-weeded. Before first frost, put metal wire hoops on and one layer of row cover. I like the variety Detroit Red.

Celeriac—start seeds in spring. Transplant to garden when big enough. Before first frost, put metal wire hoops on and one layer of row cover. Harvest all winter. I haven’t done celery over the winter but plant to this year. The schedule for growing celery is the same as for celeriac.

Chard—start late July or early August for harvest in the fall, winter, and early spring of the next year. Put wire hoops and row cover on before first frost. When it’s going to be below 20F, add additional layers of row cover and/or greenhouse plastic.

Collards, Kale (Red Russian is a good variety)—start anytime in August. Put wire hoops and row cover on before first frost. When it’s going to be down around 10F or less,, add additional layers of row cover and/or greenhouse plastic.

Lettuce—start in late August/early September. Put wire hoops and row cover on before first frost. When it’s going to be below 20F, add additional layers of row cover and/or greenhouse plastic. Lettuce is sensitive to cold and will get more protection with a wooden cold frame with row cover over top and sides. When it’s below 20F, add greenhouse plastic over the top, sides, and ends of the wooden coldframe.

Spinach—start in late August/early September. Requires no winter protection other than a mulch of light straw if you don’t want to pick it until early spring. If you want to pick it all winter, put wire hoops and row cover on before first frost. When it’s going to be down around 10F or less, add additional layers of row cover and/or greenhouse plastic.

Early Purple Sprouting Broccoli—start seeds August 1st. Transplant to garden when big enough. Protect from cabbage moths. Put wire hoops and row cover on before first frost. When it’s going to be below 20F, add additional layers of row cover and/or greenhouse plastic. Take covering off in the spring. Will take some very light frost without cover in spring. Don’t let it get too hot in the spring or it will bolt. This is a really awesome crop for early spring. You’ll be picking broccoli in March, before the cabbage moths come out and when most vegetables aren’t ready yet. Broccoli has the best flavor in March.

Hakurei turnips—start seeds in August.

Arugula—Plant in early September. Before first frost, put metal wire hoops on and one layer of row cover. Harvest all winter.

Onion family—Members of the onion family are great for harvesting all winter. Leeks, garlic, and scallions are all superb. I grow and harvest garlic year-round (I never store it inside). Leeks take awhile to grow, so plan ahead, but they will hold well in the garden for fall and winter harvest. Walking onions are wonderful because they reproduce themselves and, like garlic, can be grown in the garden year-round.

Artichokes—Artichokes are not winter-hardy without protection in the mid-Atlantic. However, they can be successfully grown as perennials and will survive the winter with the same precautions as for lettuce. They will need at least one layer of frost blanket, adding greenhouse plastic is helpful, and a wooden cold frame helps too.

This winter, I also plan to work with cabbage (there are special varieties for overwintering), mache, various Asian greens, brussel sprouts kohlrabi, salsify, radicchio, and celery, which I believe all have potential for winter harvest.

If you plan ahead well, you can supply all the fresh vegetables you need year-round, even through the winter in the mid-Atlantic region. We also freeze enough summer vegetables (green beans, okra, lima beans, peas, peppers, summer squash) and can tomatoes to last year-round. Winter squash, potatoes, and sweet potatoes store well all winter in the right environment.