Vegetables

Planting and Growing Kale

Kale is a cold-hardy, resilient vegetable that’s easy to grow and can be planted in the spring or fall. It’s also the easiest member of the brassica family to grow. (This family includes: broccoli, cabbage, brussels sprouts, and other common cole crops.) Kale comes in a wide range of varieties, from vibrant greens to rich, dark purples, to crunchy leaves to crinkled beauties, and so many others. Full sun and fertile soil will produce the fastest-growing and most tender leaves, but kale will also tolerate partial shade as well.

Planting and Growing Information:

For the spring, you can begin planting kale relatively early—4 to 6 weeks before the average last frost. Kale tastes best when plants grow quickly and mature before the summer heat (temperatures above 75°F) or after fall frosts. For the spring, you can plant 4 to 6 weeks before the typical last spring frost, whether you transfer seed into the soil or transplant start plants from the nursery. Seeds will germinate at soil temperatures as low as 40°F. For the fall, direct-seed 3 months before your first fall frost date. In areas with hot summers, you’ll need to delay sowing until temperatures begin to cool off. The cool fall weather really brings out kale’s sweet, nutty flavor, which can tolerate hard frosts (25°F to 28°F) without experiencing damage. In mild winter regions like the Southwest, Pacific Northwest, and Southeast, kale can be grown as winter vegetables under a cover or outside, and they’ll grow and yield all winter long.

Given the space between kale plants is relatively large, it’s best to begin kale off away from your prime growing areas simply because it’s a more efficient use of space. Plant seeds ¼ to ½ of an inch deep, 1 inch apart in rows 18 to 30 inches apart into well-drained, light soil with a pH range of neutral to slightly alkaline. After about two weeks, thin the seedlings so they’re spaced out 12 to 18 inches apart as kale likes to have plenty of space to stretch out. Should you be setting out young plants (transplants), plant them at the depth at which they’re growing in the container, and space them 18 to 24 inches apart. After planting, thoroughly water plants.

It's crucial to ensure that kale is well-watered and fertilized. If rain is inconsistent, provide 1 to 1½ inches of water each week (about 1 gallon per square foot). Be sure to regularly feed kale with a continuous-release plant food. To keep down the weeds and keep kale cool, mulch the soil; kale won’t grow in hot weather. Remember to heavily mulch the soil after the first hard freeze in the fall. The plants may continue to produce leaves throughout the winter.

Fertilization:

Before planting, add plenty of compost to the ground, and if your soil isn’t especially rich, increase its fertility by working in nitrogen-rich amendments like blood meal, cottonseed meal, or composted manure into the ground before planting. Meanwhile, while planting, add fertilizer (1½ cups of 5-10-10 fertilizer per 25 feet of row into the top 3 to 4 inches of soil). 

Harvesting:

Once kale leaves become the size of your hand, you are ready to harvest it. Pick about one fistful of leaves per harvest, but no more than one-third of the plant at a time. Be sure to begin harvesting the oldest leaves first from the lowest section of the plant. Discard any yellowed or torn leaves. Avoid picking the terminal bud, which is found at the top center of the plant, and is the part that keeps the plant productive. Kale will continue to grow until it’s 20°F, but don’t stop harvesting—a touch of frost makes kale even sweeter. Protect the kale with row covers to extend the harvest. You could also create a makeshift cover with tarps and old blankets propped up by hale bales.