Washington Planting Guide & Growing Season
Washington is in USDA hardiness zone 4b-9a with a growing season of 185 days. The average last spring frost is Apr 15 and the average first fall frost is Oct 15.
Growing Conditions in Washington
How Washington Compares
Compare Washington's growing conditions with states that have similar climates.
| State | USDA Zone | Last Frost | First Frost | Season (days) |
|---|---|---|---|---|
| Washington (WA) | 4b-9a | Apr 15 | Oct 15 | 185 |
| Alabama (AL) | 7a-8b | Mar 15 | Nov 5 | 235 |
| Alaska (AK) | 1a-7b | May 30 | Sep 5 | 100 |
| Arizona (AZ) | 4b-10b | Mar 1 | Nov 15 | 260 |
| Arkansas (AR) | 6b-8a | Apr 1 | Oct 25 | 210 |
| California (CA) | 4b-11a | Feb 15 | Nov 30 | 290 |
Frequently Asked Questions About Gardening in Washington
When should I start seeds indoors in Washington?
In Washington, the average last frost date is Apr 15. Start most seeds indoors 6-8 weeks before this date. The USDA hardiness zone for Washington is 4b-9a, with a growing season of approximately 185 days.
What USDA hardiness zone is Washington?
Washington falls in USDA hardiness zones 4b-9a. This affects which perennial plants will survive winter and influences optimal planting times.
When is the first frost in Washington?
The average first frost date in Washington is Oct 15. Plan to harvest cold-sensitive crops before this date or protect them with row covers.
How long is the growing season in Washington?
Washington has an average growing season of 185 days, from the last frost (Apr 15) to first frost (Oct 15). This moderate season works well for most common vegetables.
Plan Your Garden
Use our seed starting calculator to get personalized planting dates, or browse all states.