Seattle, WA · zone 8b · ~252 frost-free days

When to plant a garden in Seattle.

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.

CropStart indoorsSpring sow / set outFall sow
Tomato, slicingFeb 5 to Apr 7Mar 19 to May 19
Lettuce, leafFeb 2 to Mar 19Sep 5 to Nov 4
CarrotFeb 2 to Mar 7Aug 24 to Sep 19
Bush BeanMar 12 to May 2Aug 5 to Sep 7
Cucumber, slicingMar 19 to Jun 18Jul 19 to Aug 19
Pepper, bellFeb 14 to Apr 7Mar 28 to May 19
KaleDec 22 to Jan 19Feb 2 to Mar 2Aug 19 to Oct 4
SpinachJan 19 to Mar 2Sep 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.