When to Plant in Washington

Washington state's gardening conditions are split by the Cascades. Western Washington around Seattle and Olympia has mild, wet winters and dry summers — perfect for a long season of cool-weather crops and a good summer window for warm-season ones.

Eastern Washington around Spokane and the Yakima Valley has hot, dry summers and cold winters. The long summer days and irrigation-fed soil produce exceptional vegetables, but the shorter frost-free season requires careful timing.

Common Mistakes

Planting warm-season crops too early in western WA — cool spring soil temperatures delay growth even when air feels warm.
Not providing enough water east of the Cascades — eastern WA is semi-arid and crops need consistent irrigation.
Ignoring the maritime influence on western WA — the cool, cloudy springs delay warm-season crop timing.
Skipping season extension in eastern WA — cold frames and row covers can add weeks to both ends of the season.

FAQ

What is the last frost date?

The last frost date is the typical date in spring when your area has its final frost. After this date, it's generally safe to plant warm-season crops outdoors.

When should I start tomatoes indoors in Washington?

Start tomato seeds indoors about 6–8 weeks before your last frost date. In the Seattle area, that's typically mid-March. In eastern WA, start in late March to early April.

Can I plant before the last frost?

Yes — cool-season crops like lettuce, peas, spinach, and broccoli can handle light frost and should be planted 4–6 weeks before your last frost date.

Why does timing vary so much within Washington?

The Cascades create a dramatic climate divide. Seattle is mild and maritime while Spokane is continental. Frost dates, rainfall, and summer heat differ enormously between the two sides.

What if I live in a frost-free area?

Western Washington's coast rarely sees hard freezes, but cool temperatures limit warm-season crops. Enter your zip code in the app for exact timing based on your location.

How does Plan My Garden create my schedule?

You enter your zip code, and we look up your local frost dates. Then based on the crops you pick, we calculate when to start seeds, transplant, and harvest — personalized to your location.