Growing Guide
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Vegetable (Cool Season) - Cabbage Family

Brassica oleracea var. acephala (collards)
Brassicaceae Family

The flavor of this traditional Southern potherb is improved by frost. Very cold hardy (harvest can continue right through snow), collards are also among the most heat tolerant of cole crops.

Site Characteristics
  • full sun
Prefers full sun in spring, but can benefit from light shade during hot weather.

Soil conditions:

  • requires well-drained soil
Prefers well-drained, fertile soil high in organic matter, pH 6.0 to 7.5. Can tolerate slightly alkaline soil. Prefers plentiful, consistent moisture. Can tolerate drought, but quality and flavor of leaves suffer.
Plant Traits

Lifecycle: annual

Biennial grown as an annual.

Ease-of-care: easy

Height: 1.5 to 3 feet

Spread: 1 to 2 feet

Foliage color:

  • medium green
  • dark green

Some varieties have blue-green cast.

Foliage texture:

  • coarse
  • medium


  • cushion, mound or clump
  • upright

As plants mature and lower leaves are harvested, plants begin to look less like a clump and start to resemble small palm trees with a cluster of leaves at the top of a long stem.

Special Considerations
  • frost - Flavor improved when plants are “kissed” by frost.
Special uses:
  • edible landscaping
Growing Information
How to plant:

Propagate by seed

Germination temperature: 45 F to 85 F - Will germinate at soil temperatures as low as 40 F.

Days to emergence: 4 to 7

Seed can be saved 4 years.

Maintenance and care:
Direct seed about three months before expected fall frost. Plant seeds to inch deep, 1 inch apart in rows 18 to 30 inches apart. Thin to 12- to 18-inch spacings. Eat or transplant thinnings.

For spring crops, start plants inside about 8 weeks before the last frost, and transplant when they are about 6 weeks old. Set transplants 12 inches apart, rows 18 to 24 inches apart.

Plant direct-seeded crops 1/2 inch deep and 3 inches apart 3 weeks before last frost. Thin to 12 to 18 inches apart.

Mulch overwintering plants.

Collards don't seem to be as troubled by pests as most other cole crops. Use floating row covers to help protect from early insect infestations.

To help reduce disease, do not plant collards or other cole crops in the same location more than once every three or four years.

Cabbage loopers
Flea beetles
Cabbage root maggots
Cabbage aphids
Slugs and snails

Usually not as susceptible to pest damage as other cole crops.

Black rot
Black leg

To help reduce disease, do not plant kale or other cole crops in the same location more than once every three or four years.

Browse collards varieties at our Vegetable Varieties for Gardeners website.

Choices are usually limited in seed catalogs. Some varieties form loose heads.

Some varieties recommended for New York include:

Blue Max -- hybrid
Georgia Green