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When to Plant Delicata Squash in Whatcom County, WA

Delicata squash is a winter squash with an edible skin and sweet, creamy orange flesh. Its compact vines make it suitable for smaller gardens.

Whatcom County, Washington is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 386 feet, Whatcom County receives approximately 49 inches of rainfall annually with predominantly silt loam soil. Summer highs average 85ยฐF, providing good warmth for Delicata Squash during the growing season.

Whatcom County, WA (Zone 7b) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29

Whatcom County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (76 days to spare)
Start indoors: Feb 25 Transplant: Apr 8 🍅 Harvest: Jul 1 – Aug 5
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Mar 9 Transplant: Apr 20 🍅 Harvest: Jul 13 – Aug 17
Safe Start (90%) ✓ Fits season (66 days to spare)
Start indoors: Apr 8 Transplant: May 20 🍅 Harvest: Aug 12 – Sep 16

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
1.0″/week
Watering frequency Only during dry spells
Season total 2 gal / 100 sq ft
Delicata Squash needs ~1,238 GDD — county provides 2,832 GDD Excellent fit

Delicata Squash Planting Timeline โ€” Whatcom County, WA

Delicata Squash Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 โ€“ Mar 23
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest July 13 Jul 13 โ€“ Aug 17

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

80โ€“100 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 7b

Growing Season

206 days

Growing Tips for Whatcom County

Direct sow after last frost on mounds. Harvest when skin is hard and ivory with green stripes. The thin skin does not need peeling. Stores 2-3 months in a cool place.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Delicata Squash in Whatcom County, WA?

Whatcom County is in Zone 7b with an average last frost of April 6. Plan your Delicata Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Whatcom County, WA?

Whatcom County, Washington is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Whatcom County gardeners in Zone 7b 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 Whatcom County, WA. Local conditions may vary. Last updated: April 2026.