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When to Plant Hubbard Squash in Klickitat County, WA

Hubbard squash is a large, bumpy-skinned winter squash with dense, sweet, dry flesh ideal for baking and pies. The hard shell allows storage for 6 months or more.

Klickitat County, Washington is in USDA Zone 6b. The average last spring frost is April 14 and the first fall frost is October 19, giving you a growing season of approximately 188 days.

At an elevation of 466 feet, Klickitat County receives approximately 42 inches of rainfall annually with predominantly silt loam soil. Summer highs average 77ยฐF, so choose short-season varieties of Hubbard Squash to ensure they mature before fall.

Klickitat County, WA (Zone 6b) Moderate season
188 days
Last Spring Frost April 14
188 growing days
First Fall Frost October 19

Klickitat County Soil Profile

Soil Type

Silt Loam

Soil pH

5.3-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (32 days to spare)
Start indoors: Mar 4 Transplant: Apr 22 🍅 Harvest: Aug 5 – Sep 9
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Mar 10 Transplant: Apr 28 🍅 Harvest: Aug 11 – Sep 15
Safe Start (90%) ✓ Fits season (35 days to spare)
Start indoors: Apr 1 Transplant: May 20 🍅 Harvest: Sep 2 – Oct 7

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
0.1″/week
Watering frequency Only during dry spells
Season total 103 gal / 100 sq ft
Hubbard Squash needs ~852 GDD — county provides 1,457 GDD Excellent fit

Hubbard Squash Planting Timeline โ€” Klickitat County, WA

Hubbard Squash Planting Calendar

Activity When Date Range
Start Indoors March 10 Mar 10 โ€“ Mar 24
Transplant Outdoors April 28 Apr 28 โ€“ May 12
Direct Sow April 21 Apr 21 โ€“ May 12
Harvest August 11 Aug 11 โ€“ Sep 15

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 โ€”
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

100โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6b

Growing Season

188 days

Growing Tips for Klickitat County

Start seeds indoors in short-season areas. Requires ample space and rich soil. Harvest when the skin is very hard and the color is deep. Cure in the sun before storing.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Level Up Your Garden

Frequently Asked Questions

When should I plant Hubbard Squash in Klickitat County, WA?

Klickitat County is in Zone 6b with an average last frost of April 14. Plan your Hubbard Squash planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Klickitat County, WA?

Klickitat County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is April 14 and first fall frost is October 19.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Klickitat County gardeners in Zone 6b 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 Klickitat County, WA. Local conditions may vary. Last updated: April 2026.