The hardiest of the cool weather vegetables can survive the winter. Some of them will need protection from harsh freezing temperatures and some of them can withstand temperatures down to 10 degrees! Interestingly, the adaptation that allows them to survive, also makes them sweeter. When it gets cold, these plants convert some of their starch stores into sugar, which prevents their cells from freezing. It’s the same concept as salt on the road — the presence of salt, or in this case sugar, lowers the freezing point of water.
Lettuce, Spinach, and Cilantro are growing under plastic row covers. We follow Elliot Coleman’s four season gardening method, low tunnels heating up with the sun on cool days and protecting from crippling temperatures at night. We plant lettuce in succession to have a fresh supply throughout the winter and early spring. We’ve been using these greens nearly every week in restaurant to make a side salad that feeds 40+.
Did you know that lettuce is related to dandelions and was first cultivated by ancient Egyptians?
Spinach, like lettuce, is a part of the Amaranth family and can overwinter in temperate regions. Try planting it in the fall. It will lie dormant most of the winter and grow like crazy at the onset of warmer temperatures and longer days.
Fava Beans are native to North Africa and South Asia. They prefer cool weather and are a great plant to grow to provide some much needed green in the winter garden. We usually plant ours in November (though they can be planted as late as January) and we harvest throughout the spring. Amazingly they can handle temperatures down to 10 degrees Fahrenheit. Fava beans shelled and sauteed in garlic are simply divine.
Carrots are available in virtually all seasons. If planted in late summer or early fall, giving them enough time to develop before the ground freezes, they will overwinter in the soil. The tops will die back, but there’s nothing to stop you from foraging all winter.
Carrots are umbellifers (their flowers are like little lacy umbrellas.) If left to flower they attract predatory wasps that kill many garden pests.
Brassicas, the mustard family, includes Kale, Collards, Brussels Sprouts, Turnips & Cabbages. originated in the Mediterranean. They too can hold in cold temperatures – up to 18 degrees. Below that, we cover them with floating row cover to help them survive. This winter we are growing Brussels sprouts against a south facing brick wall. It catches the heat and slowly radiates it back out. Some happy little Haukeri turnips are waiting their turn to be harvested and the Kale has soldiered through beautifully.
Garlic is a somewhat slow growing plant, but in our opinion, well worth the wait. It’s another little plant that valiantly defends itself against most trouble, and even helps plants around it too. Most pests don’t bother garlic and neither does the cold.
We usually grow softneck garlic at GMS, planting it in late fall (about six weeks before the soil freezes) and harvest in late Spring. The students usually pull it out in the last few weeks of school and set it in the shade to cure. Like favas, they provide some much needed green in the brown world of the winter garden.