How to Grow Collard Greens USA
On this page
Collard greens (Brassica oleracea Acephala Group) — biennial grown as an annual.
Core growing advice on this page is checked against named horticultural sources — see References.
Collard Greens (Brassica oleracea Acephala Group)
2 sources cited · Verified
At a Glance
Quick Facts
| Factor | Value |
|---|---|
| Soil texture | well-drained, rich in organic matter; loam for best yields (NC State) |
| Drainage | well-drained |
| Lifecycle | biennial grown as an annual |
| Edible parts | leaves |
Soil & Growing Conditions
Water: moist but not saturated, especially during germination (NC State)
Growth Stages
| Stage | BBCH | Notes |
|---|---|---|
| Sowing | 0 | Sow 1/2 to 3/4 inch deep in early spring or midsummer; keep the top 3/4 inch of soil moist but not saturated during germination (NC State). |
| Transplanting / thinning | 3 | Transplant or thin to spacing matching the intended harvest stage: 2-4in for young leaves, 10-15in for half-grown, 15-18in for full-grown plants (NC State). |
| Leaf growth | 4 | Cold-hardy and heat-tolerant, growing well across regions; needs ample nitrogen for deep green colour and tender growth (NC State, UMD Extension). |
| Harvest | 8 | Ready 60-80 days after sowing; harvest whole plants at any stage or pick individual leaves from mature plants -- flavour sweetens after frost (UMD Extension, NC State). |
Harvest & Storage
When to pick: Ready 60-80 days after sowing (UMD Extension). Cut whole young plants (which regrow), half-grown or full-grown plants, or harvest tender leaves individually from a mature plant (NC State). Flavour turns sweeter after a few frosts.
Diseases
Pests
Collard Greens, Leaf to Harvest
Plan your Collard Greens planting
When to sow and plant Collard Greens depends on your own frost dates. Check the USA vegetable planting calendar. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.
Growing Collard Greens in another region
Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.
Sources
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Cool-season crop thriving in early spring or fall. Sow seeds in early spring or midsummer; transplant in early spring or late summer. Plant seeds 1/2 to 3/4 inch deep, never deeper than 1 inch. Spacing varies by harvest maturity: young harvest 2-4in apart, half-grown harvest 10-15in apart, full-grown harvest 15-18in apart; optimal bed configuration two to four plants wide with 12-18in between beds. Soil pH 6.0-6.5, well-drained, rich in organic matter; loamy soils give greatest yields, sandy soils suit early spring crops; incorporate 2 inches of compost seven days before planting; needs ample nitrogen for deep green colour and tender growth. Mature plant tolerates frosts and light to medium freezes. Harvest: cut entire young plants (which regrow for multiple harvests), half-grown plants, full-grown plants, or harvest tender leaves individually from mature plants. Keep top 3/4 inch of soil moist but not saturated during germination. Notable NC-performing varieties: Vates, Carolina Improved Heading, Georgia Southern, Blue Max, Heavi Crop. Pests/diseases not addressed in this document.
These 2 sources are specific to this region. The full list of 2 sources behind this guide (NC State Extension, University of Maryland Extension) is in the references of our UK guide to collard greens; they describe the plant itself, which is the same wherever it grows.
Frequently Asked Questions
What problems affect collard greens?
Our data links 2 diseases and 3 pests to this crop. See the sections above for each one and how to manage it.
Plan next season before the problems start
Almost everything on this page resolves to your own frost dates rather than the calendar — the last spring frost moves by roughly two months between zone 3 and zone 10. The USA Garden Planner works from your zone so the timing is already decided before the season starts.
Get the USA Garden Planner →Instant PDF download · Written for US growing conditions
How this guide is put together
The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against USDA hardiness-zone and frost-date data, with Cooperative Extension sources cited directly where one exists for a crop. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.
Related Problem Guides
Last verified 2026-08-29
Related guides
More from the same group (brassicas & mustards):
Growing advice for your part of the USA
Timing and conditions change a lot inside one country. These guides cover frost dates and growing seasons region by region.
Where To Go From Here
Take this crop from reading into a written plan for your own beds.
Keep going
Plan the next step
Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.