Collards are a cool-season crop. Collards thrive in temperatures between 65°F and 75°F (18-24°C) and can withstand frost down to 25°F (-4°C).
If summers are warm in your region, start collards in late winter or early spring for a late spring or early summer harvest. Where summers are cool, plant in mid-to-late spring for late summer and fall harvest. Where summers are hot, sow seed in midsummer for a late fall or early winter harvest.
Collards are very hardy and most flavorful after being hit by frost. Time your planting so that collards come to harvest in cool weather.
Collards mature in 80 days depending on the variety.
Collard sowing and planting tips
- Start collards from seed or transplants.
- Collard seeds are viable for 4 years.
- Start seeds indoors 6 to 4 weeks before the last frost in spring or 12 to 10 weeks before the first frost in fall.
- Start seeds in individual pots or flats.
- Sow seed ¼ to ½ (6-13 cm) inch deep in the seed-starting mix.
- Keep the mix moist but not wet.
- Collard seed should germinate in 5 to 10 days at an optimal temperature of 75°F (24°C) or thereabouts.
- Transplant seedlings into the garden when they are 4 to 6 inches (10-15 cm) tall with 2- to 4-leaves and daytime temperatures reach 50°F (10°C); firm transplants into the soil by hand.
- Prefers a soil pH range of 6.0 to 7.5.
- Set transplants slightly deeper than they grew in pots or flats.
- Grow collards in full sun for best yield—tolerates partial shade.
- Add 3- to 4- inches of compost and well-aged manure into planting bed, before transplanting; collards need friable, moisture-holding soil.
- Avoid planting where cabbage family crops have grown recently.
- Space plants 18 to 20 inches (45-50 cm) apart in all directions.
- Space rows 24-42 inches (60-106 cm) apart.
- Protect seedlings from the cold for 2 to 3 weeks after planting by covering them with a cloche or plastic tunnel or cold frame.
- Fertilize with an organic fertilizer such as fish emulsion at half strength.
- Common pest enemies are aphids, cabbage worms and loopers, cabbage worms, and cutworms.
More tips at: How to Grow Collards.
Interplanting: Grow collards with beets, green onions, peas, southern peas, tomatoes, or peppers.
Container Growing: A single plant will grow in a 10-inch (25 cm) pot that is 12 inches (30 cm) deep.
Collard planting calendar
For spring harvest:
- 8-7 weeks before the last frost in spring: start seeds indoors.
- 8-6 weeks before the last frost in spring: direct-sow seed in the garden under a plastic tunnel.
- 4-3 weeks before the last frost in spring: direct-sow seed in the garden without cover; minimum soil temperature should be 40°
- 3-2 weeks before the last frost in spring: transplant seedlings into the garden.
For fall and winter harvest:
- 16-14 weeks before the first frost in fall: start seed indoors.
- 14-12 weeks before the first frost in fall: direct-sow seed in the garden.
- 12-8 weeks before the first frost in fall: transplant seedlings into the garden under a plastic tunnel.
Recommended collard varieties
‘Champion’, ‘Georgia’, ‘Vates’.
Botanical Name: Brassica oleracea Acephala group
Collard is a member of the Brassicacea (Cruciferae) or cabbage family.