When to Plant Collard Greens in Washington, DC
Published: April 24, 2026
Collard Green Planting Dates for Washington, DC
| Start seeds indoors | February 15–22 |
| Last frost (average) | March 22 |
| Transplant outdoors | March 1–11 |
| Direct sow outdoors | March 1–11 |
| Minimum soil temperature | 45°F |
| Expect first harvest | April 30 – May 15 |
| Fall crop planting | September 1–11 |
| Fall crop harvest | October 31 |
| First fall frost (average) | November 10 |
⚠ Direct sow or transplant collard greens 3–4 weeks before last frost. Extremely cold hardy — withstands temps to 15°F. Can be grown as a perennial in Zones 8+. Fall planting produces the best-flavored greens.
Best Collard Green Varieties for Washington, DC
Consult a Washington-area nursery or your state extension office for collard green varieties proven in Zone 6b.
Growing Collard Greens in Washington
Washington sits in Zone 6b, with an average last frost of March 22 and first fall frost around November 10 — giving a 233-day frost-free growing season. Cool-season crops like collard green benefit from Washington's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
Washington's moderate climate supports collard green on the standard transplant calendar with minimal special accommodation. Succession planting — sowing fresh seeds or setting new transplants every 2–3 weeks through spring — stretches the harvest window and gives you a backup crop if pests hit the first planting.
Washington's mixed soil conditions vary block by block — get a soil test if you have not in three years. Generally, a base of quality compost (2 to 3 inches annually) and consistent watering at 1 inches per week serves collard green well across most soil types found in Washington.
Collard Green Calendar for Washington
| Month | Task |
|---|---|
| February | Start seeds indoors under grow lights |
| March | Transplant outdoors into warm soil |
| April | Expect first harvest window to open |
| September | Start fall crop — transplants or direct sow |
| November | First fall frost — harvest remaining, end of outdoor season |
Collard Green Tips for Washington Gardeners
- •Harvest outer leaves continuously once plants reach 10 inches — the central growing point produces for months.
- •In Zones 8+ collard greens often overwinter and produce for 2–3 years as a perennial.
- •Succession plant collard green in Washington every 2–3 weeks through spring to extend the harvest window into summer.
Common Collard Green Pests in Washington
- •Cabbage Worm — peaks July in Zone 6b (active May–September); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Aphid — peaks July in Zone 6b (active May–September); monitor closely during peak season and treat early.
- •Flea Beetle — peaks July in Zone 6b (active May–September); tiny black beetles that riddle leaves with holes; row covers protect seedlings.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Collard Greens in Washington
In Washington's moderate climate, Onion and Garlic are the most beneficial plants to grow alongside collard green. Onion deters carrot fly, aphids, and several root-zone pests through sulfur compounds. Keep collard green away from Tomato — it competes for nutrients or shares pest pressure.
Frequently Asked Questions
When should I plant collard green in Washington, DC?
In Washington (Zone 6b), start collard green seeds indoors around February 15–22 and transplant outdoors around March 1–11. The city's average last frost of March 22 is the anchor date — count 5 weeks back for seed starting and 3 weeks back for transplanting.
What zone is Washington, DC for collard green growing?
Washington is USDA Zone 6b. For collard green, this means a frost-free growing season of roughly 33 weeks running from March 22 to November 10. Cool-season crops like collard green thrive in this zone with both spring and fall planting windows available.
When is collard green harvest season in Washington?
Expect the first collard green harvest in Washington around April 30, with harvest continuing through May 15. This is based on 60–75 days from transplant or direct sow. A fall crop planted September 1–11 adds a second harvest around October 31.
How long does it take to grow collard green in Washington, DC?
From transplant or direct sow to first harvest, collard green takes 60–75 days in Washington's climate. Based on a typical planting date of March 1–11, expect your first harvest around April 30. Washington's Zone 6b transition-zone climate produces maturity times right in the middle of the stated range.
What soil does collard green need in Washington?
Washington's soil conditions vary block by block. Before planting collard green, do a soil test (most state extension offices run them for $15–30). The test reveals pH, key nutrient levels, and organic matter content, so you can amend appropriately rather than guessing. Generally, 2–3 inches of compost annually improves most soils for vegetable production.