When to Plant Collard Greens in Wyoming
Published: April 24, 2026
Wyoming gardeners in Zone 6a have a 31-week growing season for collard green (March 30 to November 1). Wyoming's spring and fall windows both work well for collard green — some gardeners plant both successions for a long harvest. This guide gives exact dates for Wyoming based on your local frost calendar.
Collard Green Planting Dates for Wyoming
| Start seeds indoors | February 23–March 2 |
| Last frost (average) | March 30 |
| Transplant outdoors | March 9–19 |
| Direct sow outdoors | March 9–19 |
| Expect first harvest | May 8 – May 23 |
| Fall crop start | August 23–September 2 |
| Fall harvest | October 22 |
| First fall frost (average) | November 1 |
⚠ 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.
Growing Collard Greens in Wyoming's Climate
Wyoming's moderate Zone 6a climate is well-suited to collard green with minimal special accommodation. The standard transplant calendar works as written, and harvest windows line up with what seed packets recommend without adjustment.
Succession planting extends your collard green harvest significantly in Wyoming. A second planting 3 to 4 weeks after the first gives you a backup in case of pest pressure and extends the total harvest window into early fall.
Common collard green pests to watch for in Wyoming include Cabbage Worm and Aphid. The first line of defense is companion planting: Onion and Garlic planted nearby discourage several of these pests by confusing host-plant identification or repelling adults before they can lay eggs. Weekly garden walks in the early morning catch problems when they're still manageable.
Collard Green Garden Calendar for Wyoming
| Month | Task | Notes |
|---|---|---|
| January | — | Dormant season |
| February | Start seeds indoors | Use grow lights; warm soil to 70–75°F for best germination |
| March | Transplant outdoors | Soil temp must be 45°F+; nighttime lows above 50°F |
| April | — | Dormant season |
| May ← | Watch for bolting | Harvest promptly; spring heat arrives quickly |
| June | — | Dormant season |
| July | — | Dormant season |
| August | Fall crop planting | Transplant or direct sow for fall harvest before frost |
| September | — | Dormant season |
| October | — | Dormant season |
| November | First frost approaches | Harvest remaining collard green; cover plants on frost nights |
| December | — | Dormant season |
Collard Green Growing Tips for Wyoming 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.
- •Wyoming's moderate climate supports succession planting — sow new transplants or seeds every 3 weeks during spring to extend the harvest window into fall.
- •Frost improves flavor dramatically — southern tradition is to wait for the first frost before harvesting.
Companion Planting for Collard Greens in Wyoming
In Wyoming's moderate climate, planting collard green with Onion and Garlic helps deter pests and improve soil. Avoid planting near Tomato and Strawberry, which inhibit collard green growth through root chemistry or shared pest pressure. See the full collard green companion planting guide for the complete list.
Frequently Asked Questions
When should I plant collard green in Wyoming?
In Wyoming (Zone 6a), start collard green seeds indoors around February 23–March 2 and transplant outdoors around March 9–19 — 3 weeks before the state's average last frost of March 30.
What is the last frost date in Wyoming?
Wyoming's average last frost date is March 30 in the state's most common Zone 6a. Frost dates vary by city — higher elevations and northern counties run 1 to 3 weeks later than the state average. See the city list below for city-level frost dates.
Can I grow collard green year-round in Wyoming?
collard green is a cool-season crop in Wyoming, with spring and fall windows. Summer heat bolts the plants before they can produce a harvestable crop. Succession planting every 2–3 weeks stretches the harvest window.
What collard green varieties grow best in Wyoming?
For Wyoming's Zone 6a, consult a local nursery or extension office for collard-greens variety recommendations.
When do I start collard green seeds indoors in Wyoming?
Start collard green seeds indoors in Wyoming around February 23–March 2, which is 5 weeks before the state's average last frost of March 30. Use grow lights and keep soil temperatures at 70–75°F for fastest germination.