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When to Plant Squash (Winter) in Maricopa County, AZ

Winter squash includes butternut, acorn, delicata, and hubbard varieties grown to full maturity with hard rinds for storage. They develop sweet, dense flesh.

Maricopa County, Arizona is in USDA Zone 9b. The average last spring frost is January 31 and the first fall frost is December 6, giving you a growing season of approximately 309 days.

At an elevation of 4,014 feet, Maricopa County receives approximately 12.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 108Β°F, so Squash (Winter) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring β€” great for early planting β€” but Squash (Winter) will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Squash (Winter) successfully. Mulch heavily to conserve soil moisture.

Maricopa County, AZ (Zone 9b) Year-round
309 days
Last Spring Frost January 31
309 growing days
First Fall Frost December 6

Maricopa County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.5

Drainage

Well Drained

Monthly Watering Guide for Squash (Winter)

Squash (Winter) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Squash (Winter) Needs Rainfall You Supplement Action
Jan 4.3" 0.9" 3.4" 🚿 Regular watering
Feb 4.3" 0.8" 3.5" 🚿 Regular watering
Mar 4.3" 0.7" 3.6" 🚿 Regular watering
Apr 4.3" 0.5" 3.8" 🚿 Regular watering
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.4" 3.9" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.3" 2" πŸ’§ Light watering
Sep 4.3" 1.9" 2.4" 🚿 Regular watering
Oct 4.3" 1.2" 3.1" 🚿 Regular watering
Nov 4.3" 0.6" 3.7" 🚿 Regular watering
Dec 4.3" 0.8" 3.5" 🚿 Regular watering

Water needs are for active growing months only (Jan–Dec in Maricopa County). Supplement amounts are based on average rainfall β€” actual needs vary with temperature, soil, and mulching.

Squash (Winter) Planting Timeline β€” Maricopa County, AZ

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors January 3 Jan 3 – Jan 17
Transplant Outdoors February 7 Feb 7 – Feb 21
Direct Sow January 31 Jan 31 – Feb 21
Harvest May 2 May 2 – Jun 27

Plant 1" deep Β· 30" apart Β· Rows 42" apart

Month-by-Month Timeline

MonthActivities
January Start Indoors Direct Sow
February Transplant Outdoors Direct Sow
March β€”
April β€”
May Harvest
June Harvest
July β€”
August β€”
September β€”
October β€”
November β€”
December β€”

Growing Conditions

β˜€οΈ Sun

Full Sun (6-8+ hours)

πŸ’§ Water

Moderate β€” regular watering

πŸ“… Days to Maturity

80–120 days

πŸ§ͺ Soil pH

Needs 6–7 Β· Your soil: N/A

πŸ—ΊοΈ USDA Zone

Zone 9b

πŸ“† Growing Season

309 days in Maricopa County

Growing Tips for Maricopa County

Direct sow after last frost on rich mounds. Allow ample space for sprawling vines. Cure harvested fruits in the sun for 10 days before storing in a cool, dry place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Squash (Winter) in Maricopa County, AZ?

Maricopa County is in Zone 9b with an average last frost of January 31. Plan your Squash (Winter) planting based on this frost date β€” see the calendar above for exact timing.

What planting zone is Maricopa County, AZ?

Maricopa County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is January 31 and first fall frost is December 6.

🌱

Plan Your Garden with Confidence

Get our free Garden Planner β€” designed to help Maricopa County gardeners in Zone 9b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Maricopa County, AZ. Local conditions may vary. Last updated: April 2026.