When to Plant Dahlia in Washington
State
Washington
Cities Covered
488
USDA Zones
5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
Plant Type
Indoor Start
📅 Planting Calendar for Washington
Based on Seattle (Zone 9a). Dates may vary by city.
Note: Washington spans multiple zones (5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b). Select your city below for more precise dates.
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Growing Dahlia in Washington
Dahlia (Dahlia pinnata) is a popular garden vegetable in Washington. The state spans USDA Hardiness Zones 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, so planting dates can vary significantly depending on your location.
For most of Washington, you should start Dahlia seeds indoors around Friday, January 9, 2026, then transplant outdoors around Friday, February 27, 2026.
For the most accurate planting dates, enter your ZIP code on our homepage or select your city from the list above.