Collard Greens

Plant Overview

Collard Greens (Brassica oleracea var. viridis) is listed in the Brassicaceae family and categorized as a vegetable with a biennial commonly grown as an annual crop life cycle. This profile summarizes growing information for hardiness, light, soil, water, seed starting, maturity, and other available cultivation details. Difficulty is listed as Easy.

Plant ID

PLT-0042

Family

Brassicaceae

Plant type

Vegetable

Life cycle

Biennial commonly grown as an annual crop

Growth habit

Upright cool-season biennial commonly grown as an annual, producing a loose rosette of large smooth edible leaves around a central stem

Mature height

Commonly about 2-3 feet tall, though some cultivars can grow taller

Mature spread

Commonly about 18-24 inches wide

Difficulty

Easy

Growing Conditions

Collard Greens is listed for full sun conditions. Water needs are listed as moderate; keep soil evenly moist to support tender leaves and steady growth while avoiding prolonged waterlogging. The database soil reference is Fertile, well-drained loam rich in organic matter with good moisture retention. The listed soil pH range is 6.0-7.0, and the listed hardiness range is 2-11 as an annual crop.

Hardiness zones

2-11 as an annual crop

Sunlight

Full sun

Soil

Fertile, well-drained loam rich in organic matter with good moisture retention

Soil pH

6.0-7.0

Water needs

Moderate; keep soil evenly moist to support tender leaves and steady growth while avoiding prolonged waterlogging

Plant spacing

Space plants roughly 18-24 inches apart, with rows about 24-36 inches apart

Seed & Germination

For seed starting, the listed germination time is Typically 5-14 days from seed when conditions are suitable and the seed depth is About 1/4-1 inch depending on seed size. The listed time to maturity is Typically 45-120 days depending on cultivar and growing conditions. Use these values as general reference points and adjust for local climate, seed source, and growing conditions.

Germination

Typically 5-14 days from seed when conditions are suitable

Germination temperature

Collard seed germinates well under cool to mild conditions, commonly around 60-75°F, with consistent moisture

Seed depth

About 1/4-1 inch depending on seed size

Sowing method

Direct sow collard seed or start seedlings in containers for transplanting; establish plants during cool weather for the best leaf quality and steady growth

Start indoors

Optional for crops that tolerate transplanting; otherwise direct sow

Transplanting

Transplant after hardening off when temperatures suit the crop

Harvest & Propagation

Days to maturity

Typically 45-120 days depending on cultivar and growing conditions

Harvest

Harvest lower outer leaves as they reach usable size while leaving the central growing point intact, or cut the entire plant when mature

Propagation

Primarily propagated by seed and commonly direct sown or started in containers for transplanting

Seed saving

Collards are biennial and must overwinter or be replanted to flower in their second year; allow seed pods to mature and dry before collecting, and isolate flowering plants from other Brassica oleracea crops to reduce cross-pollination

Pollination

If allowed to flower in the second year, collards are insect-pollinated and can cross with other Brassica oleracea crops

Garden Information

Common pests

Cabbage worms, cabbage loopers, aphids, flea beetles, diamondback moth larvae, cutworms, slugs, and root maggots

Common diseases

Clubroot, downy mildew, black rot, Alternaria leaf spot, damping-off, and other brassica diseases

Uses

Edible leaves for braising, steaming, sautéing, soups, stews, casseroles, wraps, and other savory dishes