How to grow collard greens
Brassica oleracea (Viridis) · Brassicaceae · Vegetable
Collard Greens is a cool-season vegetable in the Brassicaceae family, grown either from a direct sowing or from transplants. It wants full sun, though it tolerates a little afternoon shade in hot regions and steady, even moisture. From sowing to first pick is about 55–75 days. It is one of the toughest crops here, standing through hard frost and often improving for it.
Grower’s note: The most heat- and cold-tolerant brassica - one spring planting can crop for months if you pick lower leaves and let it keep growing. Even sweeter after frost.
Sowing
Sow about 0.5″ deep, into soil between 45–85°F — germination is quickest near 75°F. It comes up fast (5–10 days). For an early crop, start seed indoors about 5 weeks before your last spring frost and grow it under bright light.
Spacing & layout
Give each plant about 18″ along the row with roughly 24″ between rows. On a square-foot grid that is 1 per square foot. Allow at least 18″ of loose, workable soil for the roots. It grows well in containers at least 12″ deep.
Fitting it to your season
As a cool-season crop, collard greens does its best growing in the mild weather of spring and fall and tends to bolt or turn bitter in summer heat. A second sowing in late summer, timed to mature as the weather cools, is usually the better crop of the year — and light frost only sweetens it.
Quick facts
When to plant collard greens
Companions
Onion, Dill, Potato, Beet
Tomato, Pole Bean, strawberry
Common problems
Pests: cabbage worm, cabbage aphid, cabbage looper, flea beetle.
Diseases & disorders: black rot, clubroot, downy mildew.
Same family (Brassicaceae)
Rotate these so they don’t follow each other in the same bed year to year.
Figures are typical home-garden ranges from Cooperative Extension planting guides, cross-checked against multiple state sources. Your variety and conditions will vary.