When to Plant in Seattle, WA

Seattle's maritime climate is excellent for cool-season crops but challenging for warm-season vegetables. Zone 8b with a last frost around April 4, but the cool, overcast summers limit heat-loving crops like tomatoes and peppers.

Seattle gardeners thrive with a year-round approach to cool-season vegetables: kale, chard, lettuce, broccoli, and root vegetables grow nearly continuously. Warm-season crops require strategic variety selection and the warmest, most protected spots in the garden.

What to plant now in Seattle

Year-round cool season: Kale, chard, lettuce, broccoli, peas, and root vegetables grow most of the year.
Spring: Start warm-season crops indoors for Seattle's short warm season.
Summer: Tomatoes and peppers produce with the right varieties and favorable weather.
Fall: Excellent fall planting of cool-season crops — best growing season for many gardeners.

In Seattle (226 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.

Month by month in Seattle

Month	What to do
January	Plant cold-hardy greens outdoors. Order seeds. Start onion seeds indoors.
February	Start tomato and pepper seeds indoors under lights. Direct sow spinach.
March	After April 4 last frost — plant peas, lettuce, and brassicas outdoors.
April	Transplant tomatoes to warm spots. Plant beans in warm microclimates.
May	Direct sow squash and cucumbers. Watch for slugs.
June	Dry season begins. Water consistently for warm-season crops.
July	Harvest summer crops. Seattle's warmest month.
August	Plant fall cool-season crops: broccoli, kale, carrots, beets.
September	Fall planting in full swing. Plant garlic.
October	Continue cool-season harvesting. Excellent fall conditions.
November	Kale and root vegetables continue. Protect from hard frosts.
December	Harvest cold-hardy greens. Plan next year.

Frost dates for Seattle ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
98115	April 6	October 26	9a
98133	April 6	October 26	9a
98103	April 6	October 26	9a
98109	April 4	November 16	9a
98116	April 4	November 16	9a
98178	April 10	October 25	9a
98126	April 4	November 16	9a

FAQ

When is the last frost date in Seattle, WA?

Seattle's average last frost date is around April 4. However, the cool, cloudy summers are the bigger growing challenge — not the frost dates.

Can I grow tomatoes in Seattle?

Yes, but choose carefully. Select early-maturing varieties (60–70 days) like Stupice, Siletz, Early Girl, or Legend. Plant in your warmest, sunniest spot. August and September are often the best harvest months.

What grows best in Seattle?

Seattle excels at cool-season crops: kale, lettuce, chard, broccoli, peas, carrots, and root vegetables grow almost year-round. Lean into the maritime climate rather than fighting it.

How does Seattle compare to Eastern Washington for gardening?

Night and day. Spokane's hot, sunny summers are great for tomatoes, peppers, and melons — but requires irrigation. Seattle's cool, wet climate favors year-round cool-season crops but limits heat-lovers.

How does Plan My Garden help Seattle gardeners?

Enter your Seattle zip code for planting dates calibrated to the maritime climate — including specific variety recommendations for Seattle's cool summers.