Green Machines: 5 Super-Hardy Greens for Winter Meals
With just a little protection from the elements, you can keep harvesting fresh greens well into fall and winter. The trick is to choose frost-hardy crops that continue growing during the transition to colder weather and lower light levels, and to plant them early enough that they’re nearly mature by the time the day length drops below 10 hours. Here are our top 5 picks for fall & winter greens, along with timing tips to help you get the most out of your greenhouse or coldframe.
Claytonia, also known as Miner’s Lettuce, is gaining popularity as one of the most cold-tolerant salad greens and is hardy to about 0⁰F. It is easy to grow, surviving moderate frosts and multiple harvests with ease. The heart-shaped leaves have fresh, wild flavor and crunchy, succulent texture that is especially delicious with dried figs and grated parmesan. Each stem ends in beautiful, tiny white edible flowers. Succession plant every two weeks in late summer and fall – direct sow about 1/2" apart, 1/4" deep, in rows 12" apart, thinning to 4-6" apart.
Mâche, also called corn salad, is a very hardy, low growing plant that produces tight rosettes of thick glossy leaves hardy to 5⁰F. Though it takes up to two weeks to germinate, it is quite easy to grow as it was originally selected from a weed found growing in grain fields in Europe. It has a wonderful mild, nutty flavor that is excellent with citrus, pears or apples. Direct sow once temperatures have dropped below 68⁰F, (usually in mid to late August in the North) seeds 1” apart in rows 6-12” apart.
Arugula – Those familiar with the standard arugula available in the grocery stores may be surprised to learn that there are other types as well, actually part of a completely different species that is spicier and much more cold-tolerant. Unlike the strap-shaped Eruca sativas, the Diplotaxis arugulas (such as Grazia and Sylvetta Wild) are more firey, with a shorter stature and deeply lobed leaves. Direct sow wild arugulas every 2-3 weeks until 1 month before the first frost date in your area for a continuous supply through the cool months, seeds ½” apart, 1/8” deep in rows 18” apart.
If you’re not a fan of the spicy flavor of the Diplotaxis types, you may find you prefer beet greens, spinach or kale instead. Vates kale is a great broad, low-growing curly variety perfect for cold frames, offering the most impressive cold-tolerance of any kale variety and easily surviving the entire winter with minimal protection at temperatures as low as -15⁰F. Direct sow for baby kale in late summer, or start transplants for full size plants.
Spinach is the classic winter green, growing thicker and sweeter with every freeze, such that by March the leaves will be enormous and almost sugary. The heavily savoyed types, such as Giant Winter and Winter Bloomsdale, are the hardiest, and can survive in very cold climates (around 0⁰F) with only a layer of straw to cover them. The key for a successful crop is to get the plants sized up before nights dip below freezing—mid August to mid September is generally the best time to plant (by mid-August in the far North, or at least 6 weeks before your first frost date). Direct sow seeds 2” apart, ¼” deep in rows 12-18” apart. Cover with burlap or cardboard to shade and cool the soil to 60⁰F, removing the cover once the seeds have germinated.
Beet Greens are surprisingly hardy, surviving with the protection of a greenhouse or coldframe and row cover even in very cold climates, to about 10⁰F. Bull’s Blood is Eliot Coleman’s preferred leaf for overwintered salad mixes in unheated greenhouses, thanks to its hardiness and deep magenta color even in low light conditions. Direct seed every two weeks until 6 weeks before the first frost date, seeds 1/2” apart, ½” deep in rows 12-18” apart.