10 Vegetables More Cold-Hardy than Kale
On my quest to select the top vegetables for winter gardening, I invited three other gardeners from around North America to share their favorites, based on their experiences growing in winter. All of these gardeners grow in colder climates than my own here in the Kentucky mountains (zone 6b), so if you think growing in winter is out of your reach, I hope you’ll be inspired to give it a try.
Meet the Panel:
Anna, from Northern Homestead. Alberta, Canada. Zone 3a
Isis, from Little Mountain Haven. Nelson, British Columbia. Zone 5b
Connie, from Urban Overalls. Fort Collins, Colorado, USA. Zone 5b
I asked each panelist to select their top 5 vegetables for winter growing, and from their responses (and my own experience), generated this Top 10 List. Keep in mind, however, that over 20 types of vegetables are great for winter gardening — we’ve simply selected our favorites (yep… challenging, indeed!). Here they are, in order of frequency of appearance on our individual lists.
Cold winter temperatures stimulate sugar accumulation in carrots, acting as a natural antifreeze that protects the roots from freeze damage. Sow carrots in late summer, giving them time to mature into late fall, and then leave them in the ground for steady harvests throughout the winter. Green carrot tops are hardy to at least 18 °F (-8 °C), but the roots can withstand even colder temperatures. To make harvests easier, either heavily mulch carrots when really cold temperatures arrive in zones 5 and above, or cover them with a low tunnel or cold frame. Or do like Anna — she places heavy straw bales over her in-ground carrots as extra protection, since it is not unusual for her nights to reach -40 °F (-40 °C). Varieties Scarlet Nantes and Autumn King are favored by Isis in her mountain garden.
Although tender in your salads, spinach is actually a tough little plant. It overwinters easily in at least zone 6 without protection, growing slowly through winter and bouncing back in early spring. Anna reports that although spinach leaves will die back in her harsh Canadian winters, new leaves emerge from plants in spring. Spinach can look rather rough in winter without some protection, however, so grow it under cover if winter salads are your aim. Connie successfully grows spinach in cold frames, and I have had terrific luck with it under medium-weight fabric row cover. Savoy (deeply crinkled) types are much more cold-hardy than flat-leaf varieties, so choose varieties like Winter Bloomsdale and Tyee to see you through to spring.
If you’ve planted garlic in the fall (as you should), you know that the tops are remarkably resilient to hard freezes. Leeks, a close cousin, are also champions of winter gardens. Because leeks are not sensitive to day length, like many other alliums, they will continue to grow well during the shorter days of winter. Isis favors the leek varieties Bleu de Solaise and Bandit. Note that there is considerable variation in the freezing susceptibility of leek varieties; although most leeks are very cold-tolerant, the darker, blue-green varieties are most likely to survive plunges to 0 °F (-18 °C).
Kale is so yesterday. Collards are trending now, proclaimed as “the new kale” by chef Hugh Acheson on the popular television show, Top Chef. The incredible flavor of this large green is nothing new to us from the southern United States, where collards are a staple with fried chicken or a big pot of soup beans. Collards are also superior to kale when it comes to freeze-tolerance; when Lacinato and Red Russian kale are wilted and brown, collards continue to hold. Collard variety Blue Max is a favorite, with high yields, and the greatest degree of cold-hardiness (down to 0 °F/-18 °C).
Much-loved in Britain and Ireland, but somewhat forgotten elsewhere, parsnips deserve to be standard-fare on every winter dinner plate. Like carrots, parsnips accumulate sugars with fall’s first frost, and hold well in the ground throughout the entire winter. If you want to grow parsnips for winter harvests, you’ll need to start in spring — parsnips must be planted no later than early May here in zone 6, as they can take up to 130 days to mature. Connie covers her parsnips with clear plastic as extra insurance when hard freezes occur, but parsnips are generally tolerant to 0 °F (-18 °C). Isis recommends variety Hollow Crown, a great heirloom parsnip with superior flavor. If you are convinced to give parsnips a try with a sowing this spring, make sure that you buy fresh seed — parsnip seed quickly loses viability, and will fail to germinate if over a year old.
Most publications will tell you that lettuce is sensitive to freezing, but it’s is a favorite winter food of the majority of gardeners in this panel. How do we grow it? Immature plants are generally more cold-tolerant than mature plants, and many of us grow lettuce under protection and harvest it in the baby leaf stage. Cold tolerance also varies widely among lettuce varieties — generally, heat and drought-tolerant varieties are also the most cold-hardy (which makes sense, if you know how plants survive freezing temperatures). The easiest way to find out which varieties perform well in your garden climate is with a mixed seed packet, such as Wild Garden Seed’s Lettuce mix (it contains dozens upon dozens of varieties) — sow the seeds, and see which varieties survive. Although Anna must grow lettuce indoors or in a heated greenhouse in her extreme conditions, gardeners on this panel in warmer climes can successfully grow lettuce in a cold frame or low tunnel. Protected this way, adolescent lettuce can survive when outdoor temperatures dip to 10 °F (-12 °C). I’ve even had lettuce survive 5 nights below 0 °F (-18 °C) under multilayered fabric low tunnels.
Although cabbage is more frequently planted in the spring for summer harvest, it truly shines in the fall garden; it’s flavor is improved by frost, and insect pest populations are generally fewer. Although some cabbage varieties are damaged by harder freezes, there are several varieties of overwintering cabbage that hold well left unprotected in the field. Similar to spinach, the most cold-tolerant cabbages are savoy types with deeply crinkled leaves. Try January King (a Little Mountain Haven favorite), or one of its offspring, Marabel (which is already doing well as a new trial in my garden planted for winter 2015). Overwintered cabbage will need to be planted in late summer to have time to mature, so be aware that transplants may be hard to find. Luckily, most brassicas like cabbage germinate well at warm soil temperatures, so summer sowings stand a great chance of success.
If you’ve only tried spring-sown turnips, which reach maturity in warm weather, you’re probably ambivalent about growing turnips in your garden. Turnips lose much of their spiciness and accumulate sugar when they mature in cold weather. Just ask the students I mentor at my local elementary school — their crunchy and sweet Hakurei turnips are their favorite vegetable growing in their school gardens right now (yep, beating out kale). Turnips are not as cold-hardy as the other crops that made this list, so if you’re growing through the winter, make sure to give them protection. Connie also favors Hakurei, a smooth-skinned, white variety that she grows in cold frames. Although Hakurei is arguably the best turnip variety, it is also one of the least cold-tolerant, and does not survive dips below 10 °F (-12 °C) very well, even with protection, as almost the entire root rests on top of the soil. You can fix that by mulching it heavily, or by selecting a turnip variety with thicker skins and below-ground root production, like Golden Globe.
9) Mache and Claytonia
Anna and I are both big fans of these fabulous salad greens. I prefer mache’s nutty flavor to spinach, which it also beats for cold hardiness. If you don’t wish to bother with a cold frame or low tunnel, mache (also known as corn salad) easily survives winters unprotected in zone 6 and higher. Also known as miner’s lettuce, claytonia offers a striking contrast with incredibly tender, spoon-shaped leaves. Be aware that these varieties are so well-adapted to cold, that their seeds won’t germinate well in the heat of a summer garden — wait to direct-sow them after soil temperatures have dropped below 70 °F (21 °C), and as low as 40 °F (4 °C). Anna sows them in fall in an unheated greenhouse, even though in her northern climate, they won’t be ready until spring.
10) Swiss Chard
Although a popular vegetable grown for fall, chard is also remarkably cold-tolerant, surviving dips to 15 °F (-10 °C) without protection. In my experience, green or white chards are more cold-hardy than the popular multicolored variety, Bright Lights. I prefer variety Verde de Taglio for my winter growing (which also has much less of chard’s earthy flavor that my children don’t appreciate yet); Isis is a fan of Fordhook Giant. When real winter sets in, protect chard in a cold frame or low tunnel for winter harvests. Optionally, harvest all the leaves and cover the remaining chard crown with a thick layer of mulch — the plant will survive the winter, and produce new growth in the spring.
Still want to grow kale? Keep in mind that it varies widely in cold tolerance. Although Lacinato and Red Russian (Ragged Jack) are popular varieties, they don’t perform well left unprotected in zones 7 and below. Choose variety Vates — it’s proven to be the most cold-hardy kale in my garden.
Additional Winter Gardening Resources:
These books are in my personal library, and I highly recommend them (these affiliate links cost nothing extra to you, but generate advertising fees that help me support this blog):
Remember, you’re not limited to the winter vegetables that made this list — for more varieties that you could be growing this winter, check out this extensive list: my Winter Vegetable Planting Guide. And for more winter gardening resources from me, sign up for my soon-to-be-released ebook (coming January 2016), or click the winter gardening tab above.
More from Anna, at Northern Homestead:
More from Isis, at Little Mountain Haven:
More from Connie, at Urban Overalls: