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When to Plant Squash (Winter) in Alameda County, CA

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

Alameda County, California is in USDA Zone 9b. The average last spring frost is January 18 and the first fall frost is December 12, giving you a growing season of approximately 328 days.

At an elevation of 379 feet, Alameda County receives approximately 16.4 inches of rainfall annually with predominantly loam soil. Summer highs average 97Β°F, so Squash (Winter) may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Squash (Winter) successfully. Mulch heavily to conserve soil moisture.

Alameda County, CA (Zone 9b) Year-round
328 days
Last Spring Frost January 18
328 growing days
First Fall Frost December 12

Alameda County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.7

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" 3" 1.3" πŸ’§ Light watering
Feb 4.3" 3.6" 0.7" πŸ’§ Light watering
Mar 4.3" 2.6" 1.7" πŸ’§ Light watering
Apr 4.3" 1.2" 3.1" 🚿 Regular watering
May 4.3" 0.4" 3.9" 🚿 Regular watering
Jun 4.3" 0.1" 4.2" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.2" 4.1" 🚿 Regular watering
Oct 4.3" 0.6" 3.7" 🚿 Regular watering
Nov 4.3" 1.5" 2.8" 🚿 Regular watering
Dec 4.3" 3.1" 1.2" πŸ’§ Light watering

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

Squash (Winter) Planting Timeline β€” Alameda County, CA

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors December 21 Dec 21 – Jan 4
Transplant Outdoors January 25 Jan 25 – Feb 8
Direct Sow January 18 Jan 18 – Feb 8
Harvest April 19 Apr 19 – Jun 14

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

Month-by-Month Timeline

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

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

328 days in Alameda County

Growing Tips for Alameda 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 Alameda County, CA?

Alameda County is in Zone 9b with an average last frost of January 18. Plan your Squash (Winter) planting based on this frost date β€” see the calendar above for exact timing.

What planting zone is Alameda County, CA?

Alameda County, California is in USDA Hardiness Zone 9b. The average last spring frost is January 18 and first fall frost is December 12.

🌱

Plan Your Garden with Confidence

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

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

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