In her bestselling “Book of Kale,” Master Gardener Sharon Hanna reminds us that “kale has come a long way from being a throw-away garnish from the side of our plates. It is one of the oldest and most nutrient-dense vegetables on earth, not to mention incredibly beautiful in the garden."
A trip down the laneway to my vegetable patch—snug under layers of mulch and compost—affirm Hanna’s observations. While nearly everything else has succumbed to the nip of frost, not to mention the season’s increasingly shorter days, my kale plants are as robust as ever. Brilliant in hues of green and purple, with textures reminiscent of a French petticoat, the plants are a stalwart reminder that kale is the workhorse of the winter garden.
While chilling temperatures have reduced lettuces and other tender greens to mush, my kale plants have only gotten sweeter as the mercury plummets. Like other plants in the brassica family (which includes cabbages, cauliflower, broccoli, and Brussels sprouts), kale responds to colder temperatures by producing sugars to safeguard its cells. Gardening guru Steve Solomon calls this response a kind of “antifreeze.”
Whatever you call it, kale’s ability to thrive in a variety of climates and soil conditions makes it the perfect companion for winter gardening. In the Pacific Northwest, kale is a winter staple available year round. But kale also holds its own in gardens that receive a blanket of snow, awakening again February when it sloughs off winter’s dormancy and starts to grow again.
And the benefits don’t stop there. Here are ten reasons to make kale a staple in your winter garden.
Ten Reasons to Grow Kale
1. Kale has the highest concentration of vitamins, minerals, and phytonutrients of any vegetable. According to Medical News Today, one cup of cooked kale contains ten times more Vitamin C than a cup of cooked spinach. Kale is also high in vitamins A and K and minerals like copper, potassium, iron, and phosphorus.
2. Because of its tolerance to pests, kale is easy to grow organically. Pests like aphids may bother certain varieties of kale (such as Red Russian), but co-planting with other varieties will usually guarantee an ample harvest. In the same way, cabbage moths have been known to set back tender young kale plants as they emerge from the soil. Once these plants are more mature, however, their thick green leaves are usually dense enough to keep pesky insects at bay.
3. Kale is tough. If pests like deer unwittingly break into your garden over the winter and discover your kale plants, the plants will usually recover in the spring despite the setback. In fact, we purposely lop off some of our mature kale plants each spring to promote tender and vigorous growth for salads. These tiny shoots sustain us until lettuces and other spring greens replace kale as our staple green vegetable.
4. Kids love kale. Versatile enough to blend into smoothies or sauté into an omelet, kale is the chameleon of winter vegetables, equally at home when appearing at breakfast, lunch, or dinner. And if you happen to have a dehydrator? Season kale with lemon zest and nutritional yeast and dehydrate into kale chips—a surefire favorite for children of all ages.
5. Bees love kale. When kale plants mature enough to go to seed, they will first produce delicate yellow flowers that attract bees, ladybugs, and other beneficial insects. Leaving a handful of plants for the bugs increases overall garden pollination and sets the stage for new plants down the road.
6. Kale is a consummate volunteer. Self-seeding in the most unlikely of places, kale will spring to life in a ditch (or an old boot) if you let it. As plants mature, fibrous pods crack open in an ingenious seed delivery system that spreads kale progeny far and wide. Carefully transplanting these seedlings to a more desirable location or leaving them put will ensure a continuous kale harvest without ever purchasing new seeds.
7. Kale is beautiful. Appearing in a rainbow of emerald greens, reddish pinks, and the deepest of purples, kale also dresses up in black leather to appear as Tuscan or Lacinato kale—a cultivar hearkening back to the Italian Renaissance also known as black cabbage. From frilly to curly to lacy, kale adds texture to the winter garden and enlivens the harvest all year round.
8. You can eat the whole plant. Everything about kale is edible—stems, buds, blossoms and leaves. And while people traditionally remove the lower stems before steaming or dehydrating, kale stems are an excellent source of vitamins and minerals akin to broccoli. The blossoms and buds are also delicious in salads and stir-fries.
9. You don’t need a lot of space to grow kale.
While many people grow kale in the garden, kale is equally adaptable to containers on a sunny balcony or raised beds in a narrow backyard. Even those without outdoor living space can grow kale as micro-greens in the kitchen windowsill—yet another way to enjoy the benefits of this healthy, living food during the winter season.
10. Kale is delicious! Steamed, rubbed, sautéed, or dehydrated, kale adds color to dishes and tastes wonderful. As a vegetable, kale is astonishingly adaptable, working well raw or cooked, in soups and stir-fries, as a salad topping or as its main ingredient. Drink it or chew it: kale is worthy of your attention.
Tips for Growing Kale
Despite being easy to grow, kale plants will do better if certain conditions are at play. To have enough plants available for winter harvest, it’s necessary to start your seeds in summer. (Late-planted kale seeds will generally hold in the ground until spring when they resume growing, but they won’t provide over the winter months.)
1. Nourish the soil. Whether growing in a garden, a container, or a backyard flowerbed, nourish your soil. Add compost or composted manure before planting and replenish once a year. If desired, amend with a small amount of organic fertilizer such as alfalfa meal, glacial rock dust or rock phosphate.
2. Water your seedlings. While the rain may take care of your kale plants for much of the year, they need consistent moisture to germinate and make it to maturity. Keep the soil evenly moist and ensure the tender young plants don’t dry out.
3. Avoid overcrowding your seedlings. Mature kale plants need 18 to 24” of space to grow. If planted too thickly, they will compete with one another and quickly bolt. If you are direct seeding, plant more densely and thin at a later date (you can save those thinnings for salad). If you are planning to eat the plants as part of a spring salad mix, plant more densely and cut 3 to 4 times before pulling and reseeding.
4. In fall, mulch mature plants and move young seedlings to a greenhouse. Each fall we transplant volunteer seedlings to a greenhouse where they rest under cover until spring. While kale plants generally don’t like transplanting, these are our first plants to produce when temperatures are still low but daylight is increasing. The mulched plants outside the greenhouse provide a bounty for winter salads all season long. Although not producing new leaves during their winter dormancy (October to February), their mature size guarantees enough greens for the season.
5. Cut back several mature plants in spring. As noted above, lopping off the top of a mature kale plant encourages vigorous new growth. These small leaves will provide enough greens for late winter or early spring salads while you await the next crop’s tender bounty.