When to Plant Collard Greens in Mesa, AZ
Published: April 24, 2026
Collard Green Planting Dates for Mesa, AZ
| Start seeds indoors | December 11–18 |
| Last frost (average) | January 15 |
| Transplant outdoors | December 25–January 4 |
| Direct sow outdoors | December 25–January 4 |
| Minimum soil temperature | 45°F |
| Expect first harvest | February 23 – March 10 |
| Fall crop planting | October 22–November 1 |
| Fall crop harvest | December 21 |
| First fall frost (average) | December 31 |
⚠ 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 Mesa, AZ
Consult a Mesa-area nursery or your state extension office for collard green varieties proven in Zone 9b.
Growing Collard Greens in Mesa
Mesa sits in Zone 9b, with an average last frost of January 15 and first fall frost around December 31 — giving a 350-day frost-free growing season. Cool-season crops like collard green benefit from Mesa's cooler spring and fall windows, when temperatures stay in the 55–75°F sweet spot that produces the best flavor and least bolting.
In Mesa's warm climate, collard green works best as a fall, winter, and early-spring crop. Summer heat bolts most cool-season vegetables before they can produce a harvestable head or root. Plan primary plantings in October through February in Mesa, not April through June.
Mesa'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 Mesa
| Month | Task |
|---|---|
| December | Start seeds indoors under grow lights |
| January | Last frost — harden off seedlings outdoors |
| December | Transplant outdoors into warm soil |
| February | Expect first harvest window to open |
| October | Start fall crop — transplants or direct sow |
| December | First fall frost — harvest remaining, end of outdoor season |
Collard Green Tips for Mesa 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.
- •Plant cool-season collard green in Mesa during October through February — spring plantings bolt before producing a usable crop in warm zones.
Common Collard Green Pests in Mesa
- •Cabbage Worm — peaks June–August in Zone 9b (active March–October); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Aphid — peaks June–August in Zone 9b (active March–October); monitor closely during peak season and treat early.
- •Flea Beetle — peaks June–August in Zone 9b (active March–October); 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 Mesa
In Mesa's warm 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. Warm-climate gardeners especially benefit from dense, layered companion plantings that shade soil and reduce water loss.
Frequently Asked Questions
When should I plant collard green in Mesa, AZ?
In Mesa (Zone 9b), start collard green seeds indoors around December 11–18 and transplant outdoors around December 25–January 4. The city's average last frost of January 15 is the anchor date — count 5 weeks back for seed starting and 3 weeks back for transplanting.
What zone is Mesa, AZ for collard green growing?
Mesa is USDA Zone 9b. For collard green, this means a frost-free growing season of roughly 50 weeks running from January 15 to December 31. 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 Mesa?
Expect the first collard green harvest in Mesa around February 23, with harvest continuing through March 10. This is based on 60–75 days from transplant or direct sow. A fall crop planted October 22–November 1 adds a second harvest around December 21.
How long does it take to grow collard green in Mesa, AZ?
From transplant or direct sow to first harvest, collard green takes 60–75 days in Mesa's climate. Based on a typical planting date of December 25–January 4, expect your first harvest around February 23. Mesa's warm Zone 9b climate tends toward the faster end of this range — warmer soil and longer days accelerate maturity.
What soil does collard green need in Mesa?
Mesa'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.