Seattle, WA · zone 8b · ~252 frost-free days
When to plant in Seattle: frost dates and zone 8b.
In Seattle, the typical last spring frost lands around Mar 12 and the first fall frost around Nov 19, giving you about 252 frost-free days. Cool-season crops go out before the last frost; warm-season crops wait until after it.
The 2026 windows
Sow dates for Seattle, keyed to your frost.
| Crop | Start indoors | Spring sow / set out | Fall sow |
|---|---|---|---|
| Tomato, slicing | Feb 5 to Apr 7 | Mar 19 to May 19 | — |
| Lettuce, leaf | — | Feb 2 to Mar 19 | Sep 5 to Nov 4 |
| Carrot | — | Feb 2 to Mar 7 | Aug 24 to Sep 19 |
| Bush Bean | — | Mar 12 to May 2 | Aug 5 to Sep 7 |
| Cucumber, slicing | — | Mar 19 to Jun 18 | Jul 19 to Aug 19 |
| Pepper, bell | Feb 14 to Apr 7 | Mar 28 to May 19 | — |
| Kale | Dec 22 to Jan 19 | Feb 2 to Mar 2 | Aug 19 to Oct 4 |
| Spinach | — | Jan 19 to Mar 2 | Sep 5 to Oct 24 |
Seattle sits in Zone 8b, but two gardens in the same city can be a week or two apart. The planner works from your ZIP code's frost dates, not the zone, so the dates land right for your block, not the metro average.
Build your Seattle garden plan.
Tell the free planner what you want to eat and who you're feeding. It returns plant counts, spacing, and frost-safe sow dates for ZIP 98104 in about 60 seconds.
Seattle planting questions
What planting zone is Seattle, WA?+
Seattle is in USDA hardiness zone 8b. Growing zone, gardening zone, and planting zone all mean the same thing: the USDA number, 8b here. It tells you what survives winter, not when to plant. Frost dates set your planting time, and the free planner uses your exact ZIP code's frost dates, which can differ by weeks across one metro.
When is the last frost date in Seattle?+
The typical last spring frost in Seattle, WA is around Mar 12. That is an average from local history, not a guarantee, so tender crops like tomatoes and peppers are safer with a week of buffer after it.
When is the first frost date in Seattle?+
The typical first fall frost in Seattle, WA arrives around Nov 19, closing a growing season of roughly 252 frost-free days. Count backward from it to find the last date a fall crop can still finish.
What can I plant now in Seattle?+
It depends on the date. Cool-season crops like lettuce, kale, and spinach go out weeks before the last frost; warm-season crops like tomatoes and peppers wait until after Mar 12. The table above shows each crop's window; the free planner turns your ZIP into an exact, dated calendar.