Cool-Season Vegetable

When to Plant Cauliflower in Washington

The diva of the brassica family. More temperamental than broccoli but worth the extra attention.

The Short Answer

Western Washington's cool, consistent climate is excellent for cauliflower — the same maritime conditions that make the region challenging for tomatoes make it ideal for demanding brassicas. The Puget Sound region can produce cauliflower from spring through fall without the temperature stress that ruins the crop elsewhere.

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

Cauliflower 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
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

Puget Sound (Zones 8b, 9a)

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

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first 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
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

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

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

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks before frost
Fall Planting
10 wks before first frost

Growing Cauliflower in Washington

State-Specific Growing Tips

Western Washington: transplant from March for summer heads. Fall transplant in July for autumn harvest. The cool, consistent Puget Sound climate provides the steady temperatures cauliflower demands — this is one of the few regions in the country where spring cauliflower is as reliable as fall. Eastern Washington: fall only — summer heat causes buttoning. Transplant late July.

Recommended Varieties for Washington

Everything works in western Washington. Snow Crown, Amazing, Romanesco (stunning fractal heads), purple and orange varieties. The maritime climate accommodates even slow-maturing varieties. WSU Extension rates cauliflower highly for western Washington.

Common Challenges in Washington

Slugs on young transplants. Cabbage root maggot. Clubroot in acidic maritime soils — add lime. Cabbage worms. In eastern Washington, summer heat prevents spring cauliflower.

Growing Tips

Blanch white varieties by tying outer leaves over the head when it reaches 2 inches. Temperature swings cause buttoning.

Companion Planting

Plant cauliflower alongside these companions for better growth:

Beets Celery Onions

Keep cauliflower away from:

Strawberries Tomatoes

The Bottom Line

Cauliflower 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

Cauliflower Growing Guide National planting guide with all states Washington Planting Calendar All plants for Washington Cauliflower in Alabama Alabama planting dates Cauliflower in Alaska Alaska planting dates Cauliflower in Arizona Arizona planting dates Cauliflower 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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