When to Plant Kale in Surprise, AZ
Published: April 24, 2026
Kale Planting Dates for Surprise, AZ
| Start seeds indoors | December 11–18 |
| Last frost (average) | January 15 |
| Transplant outdoors | December 18–28 |
| Direct sow outdoors | December 18–28 |
| Minimum soil temperature | 40°F |
| Expect first harvest | February 11 – March 3 |
| Fall crop planting | November 5–15 |
| Fall crop harvest | December 30 |
| First fall frost (average) | December 31 |
⚠ Plant kale 3–5 weeks before last frost for spring. Best planted in late summer (6–8 weeks before first fall frost) for fall/winter harvest. Frost sweetens the flavor.
Best Kale Varieties for Surprise, AZ
Consult a Surprise-area nursery or your state extension office for kale varieties proven in Zone 9b.
Growing Kale in Surprise
Surprise 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 kale benefit from Surprise'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 Surprise's warm climate, kale 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 Surprise, not April through June.
Surprise's caliche soil is rock-hard below the surface — raised beds filled with quality potting mix are the most practical approach for kale. 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.
Kale Calendar for Surprise
| 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 |
| November | Start fall crop — transplants or direct sow |
| December | First fall frost — harvest remaining, end of outdoor season |
Kale Tips for Surprise Gardeners
- •Harvest outer leaves first using the cut-and-come-again method; the central growing point will produce for months.
- •Kale leaves become sweeter after the first frost as plants convert starches to sugars — wait for cold nights for best flavor.
- •Plant cool-season kale in Surprise during October through February — spring plantings bolt before producing a usable crop in warm zones.
Common Kale Pests in Surprise
- •Cabbage Worm — peaks June–August in Zone 9b (active March–October); green caterpillars on brassicas; apply Bt spray or use row covers.
- •Cabbage Looper — peaks June–August in Zone 9b (active March–October); loop-walking green caterpillars; Bt spray works well.
- •Aphid — peaks June–August in Zone 9b (active March–October); monitor closely during peak season and treat early.
Check plants every 2–3 days during peak season — early intervention prevents most infestations from becoming serious.
What to Plant with Kale in Surprise
In Surprise's warm climate, Onion and Garlic are the most beneficial plants to grow alongside kale. Onion deters carrot fly, aphids, and several root-zone pests through sulfur compounds. Keep kale 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 kale in Surprise, AZ?
In Surprise (Zone 9b), start kale seeds indoors around December 11–18 and transplant outdoors around December 18–28. The city's average last frost of January 15 is the anchor date — count 5 weeks back for seed starting and 4 weeks back for transplanting.
What zone is Surprise, AZ for kale growing?
Surprise is USDA Zone 9b. For kale, this means a frost-free growing season of roughly 50 weeks running from January 15 to December 31. Cool-season crops like kale thrive in this zone with both spring and fall planting windows available.
When is kale harvest season in Surprise?
Expect the first kale harvest in Surprise around February 11, with harvest continuing through March 3. This is based on 55–75 days from transplant or direct sow. A fall crop planted November 5–15 adds a second harvest around December 30.
How long does it take to grow kale in Surprise, AZ?
From transplant or direct sow to first harvest, kale takes 55–75 days in Surprise's climate. Based on a typical planting date of December 18–28, expect your first harvest around February 11. Surprise's warm Zone 9b climate tends toward the faster end of this range — warmer soil and longer days accelerate maturity.
What soil does kale need in Surprise?
Surprise's caliche subsoil is effectively rock — traditional in-ground planting of kale 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.