When to Plant Pumpkins in Arizona
Published: April 24, 2026
Arizona gardeners in Zone 9b enjoy an extended 50-week growing season for pumpkin. Warm-climate gardeners can grow two pumpkin crops — a spring planting and a fall planting — with summer heat as the main challenge to work around. This guide gives exact dates for Arizona based on your local frost calendar.
Pumpkin Planting Dates for Arizona
| Start seeds indoors | December 25–January 1 |
| Last frost (average) | January 15 |
| Transplant outdoors | January 22–February 1 |
| Direct sow outdoors | January 22–February 1 |
| Expect first harvest | April 7 – May 2 |
| First fall frost (average) | December 31 |
Dates above assume Zone 9b, the most common zone in Arizona. Gardeners in cooler San Tan Valley (Zone 7b) plant 1–2 weeks later; warmer Tucson (Zone 9a) can plant 1–2 weeks earlier.
⚠ Count back 75–100 days from desired harvest date. For Halloween harvest, plant late June to mid-July. Plant 1–2 weeks after last frost.
Growing Pumpkins in Arizona's Climate
Arizona's warm Zone 9b climate gives pumpkin more than enough heat — in fact, peak summer heat (95°F+) can shut down fruit set entirely. The solution most Arizona gardeners use is a two-season approach: a spring crop planted early, a harvest break during peak summer, and a fall crop planted July through August for October and November harvest.
Variety selection matters more in warm climates than most gardeners realize. Choose heat-tolerant varieties bred for Arizona-like conditions — local extension offices and nurseries stock these specifically. Afternoon shade cloth during July and August can be the difference between a working fall crop and total flower drop.
Common pumpkin pests to watch for in Arizona include Squash Vine Borer and Squash Bug. The first line of defense is companion planting: Corn and Bush Bean 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.
Pumpkin Garden Calendar for Arizona
| Month | Task | Notes |
|---|---|---|
| January | Transplant outdoors | Soil temp must be 60°F+; nighttime lows above 50°F |
| February | — | Off-season |
| March | — | Off-season |
| April | First harvest window opens | Pumpkin begins producing 75–100 days after transplant |
| May ← | — | Off-season |
| June | Peak growth; water 1 inch/week | Monitor for pests daily; stake or support as needed |
| July | Continue care | Consistent watering; remove yellow leaves |
| August | — | Off-season |
| September | — | Off-season |
| October | — | Off-season |
| November | — | Off-season |
| December | Start seeds indoors | Use grow lights; warm soil to 70–75°F for best germination |
Pumpkin Growing Tips for Arizona Gardeners
- •For Halloween pumpkins, count back 75–100 days from October 31 — plant between late June and mid-July in most climates.
- •Plant on hills or mounds to warm soil and improve drainage; two plants per hill is plenty.
- •Arizona's summer heat shuts down pumpkin flowering at 95°F+. Choose heat-tolerant varieties and use shade cloth from mid-June through August to preserve fruit set.
- •Rotate pumpkins away from squash, cucumber, and melon beds on a 3-year cycle to break disease cycles.
Companion Planting for Pumpkins in Arizona
In Arizona's warm climate, planting pumpkin with Corn and Bush Bean helps deter pests and improve soil. Avoid planting near Potato and Summer Squash, which inhibit pumpkin growth through root chemistry or shared pest pressure. See the full pumpkin companion planting guide for the complete list.
Pumpkins Planting Dates by City in Arizona
Top cities in Arizona — select for city-level frost dates and planting calendars.
Frequently Asked Questions
When should I plant pumpkin in Arizona?
In Arizona (Zone 9b), start pumpkin seeds indoors around December 25–January 1 and transplant outdoors around January 22–February 1 — 1 weeks after the state's average last frost of January 15.
What is the last frost date in Arizona?
Arizona's average last frost date is January 15 in the state's most common Zone 9b. 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 pumpkin year-round in Arizona?
Not year-round — Arizona's cold season stops pumpkin production. The pumpkin season runs January 15 to December 31, roughly 50 weeks.
What pumpkin varieties grow best in Arizona?
For Arizona's Zone 9b, consult a local nursery or extension office for pumpkins variety recommendations.
When do I start pumpkin seeds indoors in Arizona?
Start pumpkin seeds indoors in Arizona around December 25–January 1, which is 3 weeks before the state's average last frost of January 15. Use grow lights and keep soil temperatures at 70–75°F for fastest germination.