Garden Scheme

Plant library  ·  Vegetables

Collard Greens

Brassica oleracea var. viridis

Collard greens are a leafy annual that can reach about 3 feet tall and 2 feet wide, bringing a substantial upright presence to a vegetable bed. Their heat tolerance makes them useful for carrying leaf production through summer, while the harvest window can stretch from late spring into winter. Pick outer leaves as they become usable and leave the center growing, so each plant remains productive rather than serving as a one-cut crop.

Sunlight Full Sun
Water Regular
USDA zones 2–11
Spacing 1.5 ft
Mature size 3 ft tall, 2 ft wide
Harvest Late spring - winter

Placement and use

Give collard greens a sunny position where their height will not overtake lower crops nearby. Set them toward the back of a bed viewed from one side, or in the center of a wider bed that can be reached from both sides; avoid placing mature plants against a narrow path. Beans, celery, dill, onions, chamomile, thyme, and lettuce can share the surrounding plan. Keep strawberries, tomatoes, and peppers in separate planting areas.

Spacing and mature footprint

Plant collard greens 18 inches apart, center to center, for a continuous row or block. Each plant can spread about 2 feet wide at maturity, so the leaves may knit together across that spacing; reserve a clear bed edge or nearby path for harvesting rather than expecting open gaps between plants. In a narrow bed, use a single row. In a wider bed, keep the block shallow enough to reach the inner plants without stepping into the soil.

Three plants set 1.5 ft apart, center to center; shaded circles show the 2 ft mature spread.

Sun, water, and soil

Use a full-sun bed and maintain regular watering so the crop does not compete with drought-tolerant planting zones. A bed with well-drained, organic-matter-rich soil gives collards room for steady leafy growth. Keep irrigation access close at hand, especially when plants are filling their mature footprint and repeated harvests are underway.[1][2]

Seasonal notes

Allow roughly 60 days to maturity when reserving bed space. Collard greens can occupy the same area from late spring through winter, so avoid following them immediately with another crop that needs the bed on a fixed midsummer date. For a fall planting, the crop can continue producing leaves into cold weather, extending the usefulness of a bed after many warm-season vegetables have finished.

Planning caveats

Treat collards as part of a multi-year rotation rather than returning them repeatedly to the same brassica bed. Leave a four-year break before using the same space again for collards or closely related cole crops such as cabbage, broccoli, cauliflower, kale, mustard, turnip, or rutabaga. Mark the bed in the garden plan so later seasonal layouts preserve that rotation interval.[1]

Growing facts

Botanical name
Brassica oleracea var. viridis
Type
Vegetable
Category
Vegetables
Lifecycle
annual
USDA hardiness zones
2–11
Sunlight
Full Sun
Water
Regular
Plant spacing
1.5 ft
Mature size
3 ft tall, 2 ft wide
Days to maturity
60
Harvest season
Late spring - winter
Pollinator friendly
No
Deer resistant
No
Native to North America
No

References

  1. Growing collards and kale in home gardens — University of Minnesota Extension
  2. Collard Greens — NC State Extension Publications

Editorial content updated 2026-07-20.