Warm-Season Vegetable

When to Plant Pumpkins in Washington

From jack-o-lanterns to pies, pumpkins need space and time but deliver a uniquely satisfying harvest.

The Short Answer

Washington's pumpkin growing splits along the familiar east-west divide. Eastern Washington's hot summers and defined fall season produce outstanding pumpkins with minimal disease pressure. Western Washington can grow pumpkins successfully — the crop needs less heat than tomatoes or peppers — but the cool, wet autumn can challenge curing and storage. Many Puget Sound gardeners discover that pumpkins are one of the more achievable warm-season crops in their marine climate.

Washington Frost Dates

Your planting dates depend on which part of Washington you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Western Washington (Seattle/Tacoma) 8a, 8b Mar 25 - Apr 15 Oct 25 - Nov 15
Puget Sound 8b, 9a Mar 15 - Apr 5 Nov 1 - Nov 20
Eastern Washington 5b, 6a, 6b, 7a Apr 25 - May 15 Sep 25 - Oct 15
Central Washington 6a, 6b, 7a Apr 20 - May 10 Oct 1 - Oct 20

Pumpkins Planting Schedule for Washington

Western Washington (Seattle/Tacoma) (Zones 8a, 8b)

Average last frost: Mar 25 - Apr 15 · Average first frost: Oct 25 - Nov 15

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Puget Sound (Zones 8b, 9a)

Average last frost: Mar 15 - Apr 5 · Average first frost: Nov 1 - Nov 20

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Eastern Washington (Zones 5b, 6a, 6b, 7a)

Average last frost: Apr 25 - May 15 · Average first frost: Sep 25 - Oct 15

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Central Washington (Zones 6a, 6b, 7a)

Average last frost: Apr 20 - May 10 · Average first frost: Oct 1 - Oct 20

Start Seeds Indoors
3 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Growing Pumpkins in Washington

State-Specific Growing Tips

Eastern Washington: plant from mid-May to early June. The hot, dry conditions grow vigorous vines and disease-free fruits. Western Washington: plant from late May to mid-June. Pumpkins grow surprisingly well in the Puget Sound region — better than tomatoes because they tolerate cooler nights. The challenge is fall rain during curing — harvest before heavy October rains and cure in a covered, ventilated area. Black plastic mulch warms soil in western WA. Space hills 5-6 feet apart.

Recommended Varieties for Washington

Eastern Washington: any variety thrives — Howden, Connecticut Field, Sugar Pie, Cinderella. Western Washington: choose shorter-season varieties (under 100 days) — Jack Be Little (90 days), Sugar Pie (100 days), Small Sugar (100 days). In the maritime climate, semi-bush varieties reduce sprawl in smaller gardens. WSU Extension provides variety recommendations for both regions.

Common Challenges in Washington

In western Washington, slugs attack young seedlings. Powdery mildew appears but is less aggressive than in the humid East. The main autumn challenge is rain — wet conditions can cause fruit rot on the ground and make curing difficult. Harvest before rains arrive. Eastern Washington: minimal pest and disease pressure in the dry climate. Squash vine borer is rare in Washington.

Growing Tips

Count backwards from when you want ripe pumpkins (usually October). They need 90-120 days, so mid-June to early July is often ideal.

Companion Planting

Plant pumpkins alongside these companions for better growth:

Corn Beans Marigolds

Keep pumpkins away from:

Potatoes

The Bottom Line

Pumpkins can be grown successfully in Washington with proper attention to regional frost dates and local growing conditions. Timing varies across the state — Western Washington (Seattle/Tacoma) gardeners work with a last frost around Mar 25 - Apr 15, while Central Washington sees frost end around Apr 20 - May 10. Choose varieties suited to your region, amend your soil based on its specific needs, and monitor for the pests and diseases most common in your area. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Pumpkins Growing Guide National planting guide with all states Washington Planting Calendar All plants for Washington Pumpkins in Alabama Alabama planting dates Pumpkins in Alaska Alaska planting dates Pumpkins in Arizona Arizona planting dates Pumpkins in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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