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When to Plant Squash (Winter) in Butte 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.

Butte County, California is in USDA Zone 9a. The average last spring frost is April 20 and the first fall frost is November 10, giving you a growing season of approximately 204 days.

At an elevation of 144 feet, Butte County receives approximately 44.8 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Squash (Winter) during the growing season.

Butte County, CA (Zone 9a) Long season
204 days
Last Spring Frost April 20
204 growing days
First Fall Frost November 10

Butte County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (52 days to spare)
Start indoors: Feb 26 Transplant: Apr 2 🍅 Harvest: Jun 25 – Aug 20
Recommended (50%) ✓ Fits season (57 days to spare)
Start indoors: Mar 23 Transplant: Apr 27 🍅 Harvest: Jul 20 – Sep 14
Safe Start (90%) ✓ Fits season (57 days to spare)
Start indoors: Apr 26 Transplant: May 31 🍅 Harvest: Aug 23 – Oct 18

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 823 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Squash (Winter) needs ~1,750 GDD — county provides 3,570 GDD Excellent fit

Squash (Winter) Planting Timeline โ€” Butte County, CA

Squash (Winter) Planting Calendar

Activity When Date Range
Start Indoors March 23 Mar 23 โ€“ Apr 6
Transplant Outdoors April 27 Apr 27 โ€“ May 11
Direct Sow April 20 Apr 20 โ€“ May 11
Harvest July 20 Jul 20 โ€“ Sep 14

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

80โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 9a

Growing Season

204 days

Growing Tips for Butte 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Squash (Winter) in Butte County, CA?

Butte County is in Zone 9a with an average last frost of April 20. Plan your Squash (Winter) planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Butte County, CA?

Butte County, California is in USDA Hardiness Zone 9a. The average last spring frost is April 20 and first fall frost is November 10.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Butte County gardeners in Zone 9a 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 Butte County, CA. Local conditions may vary. Last updated: April 2026.