Collards and Kale (cont)
By: Deborah Wechsler
How to Grow
Both of these hardy greens grow best in cool weather and rich soil, with plenty of moisture. In general, sow seeds 1/2 inch deep six weeks before you want to plant them in the garden. Space plants two to 2 1/2 feet apart and feed lightly. Mulch helps to keep soil cool and moist.
Kale and collards can survive winter temperatures as low as 5° to 10° F if they are gradually acclimatized, but sudden cold snaps can be deadly. Kale is somewhat more cold hardy, and collards are a little more heat tolerant.
In cooler regions, plant either in spring for a midsummer crop or anytime up to midsummer for harvest in fall to early winter. Says Rob Johnston of Johnny's Selected Seeds in Albion, Maine, "We plant kale from late June to late July and eat it until Christmas." They could follow the same schedule with collards, too.
In the South, late summer is the best time to plant. Here in North Carolina, I should start seed in August, but I tend to forget during the dog days. So I often buy my plants in early fall. I've had success using polyester row covers, which will keep kale and collards growing much later into the fall, plus keep pests away. We eat the greens into winter, and, in a good year, until March when they bolt into flower.
Thelma Reaves is a veteran gardener in Ayden, the home of the North Carolina Collard Festival held every September. Collards are prominent in her three- to four-acre market garden. She's nearer the ocean and her climate is milder than mine, so she has a slightly different schedule. "In October I start seed outdoors in a protected spot, then transplant to the field in January," she says. By March she is selling greens from plants that keep cropping straight through summer and fall into the following spring when they finally bloom. But in hot, dry weather, "collards just aren't fit to eat," says Thelma.
Her method of fall-seeding collards for midwinter transplants can be tricky. If the plants are too small, they won't survive the cold. If too large, they flower prematurely in spring, a condition called vernalization. According to Doug Sanders, North Carolina State University Extension horticulturist, plants with more than six to eight leaves will vernalize. The area where spring collards may be fall-planted, says Sanders, stretches up the coast into New Jersey--about USDA Zone 7.