When to Plant Collard Greens in St. George, UT
Published: April 24, 2026
Collard Green Planting Dates for St. George, UT
| 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 St. George, UT
Consult a St. George-area nursery or your state extension office for collard green varieties proven in Zone 6b.
Growing Collard Greens in St. George
St. George 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 St. George's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
St. George'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.
St. George's caliche soil is rock-hard below the surface — raised beds filled with quality potting mix are the most practical approach for collard green. Breaking through caliche for in-ground planting requires significant soil amendment, gypsum application, and deep tilling over several seasons. Water at 1 inches per week delivered through drip irrigation for best results in a raised-bed system.
Collard Green Calendar for St. George
| 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 St. George 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 St. George every 2–3 weeks through spring to extend the harvest window into summer.
Common Collard Green Pests in St. George
- •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 St. George
In St. George'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 St. George, UT?
In St. George (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 St. George, UT for collard green growing?
St. George 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 St. George?
Expect the first collard green harvest in St. George 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 St. George, UT?
From transplant or direct sow to first harvest, collard green takes 60–75 days in St. George's climate. Based on a typical planting date of March 1–11, expect your first harvest around April 30. St. George's Zone 6b transition-zone climate produces maturity times right in the middle of the stated range.
What soil does collard green need in St. George?
St. George's caliche subsoil is effectively rock — traditional in-ground planting of collard green produces poor results. Build a raised bed with 12–18 inches of quality potting mix or Mel's Mix for reliable production. Break through caliche only for deep-rooted crops, and expect to add compost each year to offset the alkalinity.