Cool-Season Vegetable

When to Plant Broccoli in Washington

A nutrition powerhouse that thrives in cool weather. Harvest the main head, then enjoy weeks of side shoots.

The Short Answer

Western Washington is outstanding broccoli country — the cool, maritime climate provides exactly the conditions the crop demands, and broccoli can produce from April through November in the Puget Sound region. This is one crop where western Washington's 'weakness' (cool summers) is an absolute strength.

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

Broccoli 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
Direct Sow
4 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
Direct Sow
4 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
Direct Sow
4 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
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Growing Broccoli in Washington

State-Specific Growing Tips

Western Washington: start transplants indoors in February, set out from March. Direct sow from April. The cool Puget Sound summer means broccoli never bolts from heat — production continues through July and August when the rest of the country has given up on spring broccoli. Fall broccoli from a July transplanting produces through November. Eastern Washington: spring transplant from late March, fall transplant from late July. Summer is too hot for broccoli. WSU Extension considers broccoli a top-tier crop for western Washington.

Recommended Varieties for Washington

In western Washington, grow anything — the climate accommodates even the slowest-maturing varieties. Marathon, Belstar, and Purple Sprouting (an overwintering type that produces in early spring) are popular. Eastern Washington: choose faster-maturing varieties for the compressed cool windows.

Common Challenges in Washington

Cabbage worms and cabbage aphids — Bt and row cover are standard approaches. Slugs on young transplants in western Washington's damp conditions. Clubroot in acidic maritime soils — add lime. In eastern Washington, summer heat causes bolting in spring plantings.

Growing Tips

Harvest main head while buds are tight. Side shoots will continue producing for weeks after the main harvest.

Companion Planting

Plant broccoli alongside these companions for better growth:

Beets Celery Onions Potatoes

Keep broccoli away from:

Tomatoes Peppers Strawberries

The Bottom Line

Broccoli 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

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