Calendars by city / WA
Seattle, Washington vegetable planting calendar
Planting windows for Seattle, Washington built from the NOAA 1991–2020 freeze normals at SEATTLE TACOMA INTERNATIONAL AIRPORT, WA US (station USW00024233), not from a hardiness zone.
Seattle, Washington planting dates for 27 vegetables
The same windows as a table
Each row applies a published extension rule to the frost dates above. Hardy crops go out 2–4 weeks before the last frost; semi-hardy crops 0–2 weeks before; tender crops around the frost date; very tender crops 2 or more weeks after. The last fall planting date counts the crop's days to harvest back from the first fall frost. The rules and their sources are on the methodology page.
| Crop | Frost class | Start seeds indoors | Plant outdoors | Last fall planting | Days to harvest |
|---|---|---|---|---|---|
| Beets | Semi-hardy | — (direct sow) | Direct sow: Feb 22 – Mar 8 | Sep 29 | 60 |
| Broccoli | Hardy | Dec 21 – Jan 18 | Transplant: Feb 8 – Feb 22 | Oct 1 | 65 (from transplant) |
| Cabbage | Hardy | Dec 21 – Jan 18 | Transplant: Feb 8 – Feb 22 | Sep 11 | 85 (from transplant) |
| Carrots | Semi-hardy | — (direct sow) | Direct sow: Feb 22 – Mar 8 | Sep 19 | 70 |
| Cauliflower | Semi-hardy | Jan 4 – Feb 1 | Transplant: Feb 22 – Mar 8 | Sep 24 | 65 (from transplant) |
| Kohlrabi | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 16 | 50 |
| Lettuce (leaf) | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 6 | 60 |
| Onions (green) | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 6 | 60 |
| Onions (dry, from seed) | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Aug 17 | 110 |
| Onions (dry, from sets) | Hardy | — (direct sow) | Plant sets: Feb 8 – Feb 22 | Aug 17 | 110 |
| Parsnips | Semi-hardy | — (direct sow) | Direct sow: Feb 22 – Mar 8 | Sep 19 | 70 |
| Peas | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 1 | 65 |
| Potatoes | Semi-hardy | — (direct sow) | Plant seed potatoes: Feb 22 – Mar 8 | Jul 26 | 125 |
| Radishes | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Nov 5 | 30 |
| Spinach | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 26 | 40 |
| Swiss chard | Semi-hardy | — (direct sow) | Direct sow: Feb 22 – Mar 8 | Sep 29 | 60 |
| Turnips | Hardy | — (direct sow) | Direct sow: Feb 8 – Feb 22 | Oct 16 | 50 |
| Snap beans | Tender | — (direct sow) | Direct sow: Mar 8 – Mar 15 | Sep 22 | 60 |
| Cantaloupe | Very tender | Mar 1 – Mar 22 | Direct sow (or transplant): Mar 22 – Apr 5 | Aug 28 | 85 |
| Sweet corn | Tender | — (direct sow) | Direct sow: Mar 8 – Mar 15 | Aug 23 | 60–90 |
| Cucumbers | Tender | Feb 15 – Mar 1 | Direct sow (or transplant): Mar 8 – Mar 15 | Sep 27 | 55 |
| Eggplant | Very tender | Jan 18 – Feb 22 | Transplant: Mar 22 – Apr 5 | Sep 22 | 60 (from transplant) |
| Peppers | Very tender | Jan 25 – Feb 22 | Transplant: Mar 22 – Apr 5 | Sep 12 | 70 (from transplant) |
| Tomatoes | Very tender | Feb 1 – Mar 1 | Transplant: Mar 22 – Apr 5 | Sep 17 | 65 (from transplant) |
| Summer squash | Tender | Feb 15 – Mar 1 | Direct sow (or transplant): Mar 8 – Mar 15 | Oct 2 | 50 |
| Winter squash | Very tender | Mar 1 – Mar 22 | Direct sow (or transplant): Mar 22 – Apr 5 | Aug 13 | 100 |
| Watermelon | Very tender | Mar 1 – Mar 22 | Direct sow (or transplant): Mar 22 – Apr 5 | Aug 28 | 85 |
What the Seattle, Washington frost-free season means for your choices
At 258 frost-free days, Seattle, Washington gardeners should compare that number to the days-to-harvest column before buying seed. A crop whose days to harvest plus its transplant age is close to the season length needs either an early start indoors or a short-season variety.
- Hardy crops (peas, spinach, radishes, lettuce, broccoli, cabbage) can go in from about Feb 8 – Feb 22 and again for fall.
- Very tender crops (tomatoes, peppers, eggplant, melons, winter squash) should wait until Mar 22 – Apr 5; start tomato seeds indoors Feb 1 – Mar 1.
- Fall sowing is worthwhile only for the rows that show a separate fall date; for the others the spring window already covers the season.
Seattle, WA planting questions
When is the last frost in Seattle, Washington?
The 50% probability date for the last spring 32°F reading at SEATTLE TACOMA INTERNATIONAL AIRPORT, WA US is Mar 8, from the NOAA 1991–2020 climate normals. In half the years on that record the last frost came later than that date, so tender crops are safer a week or two after it. The last 28°F hard freeze averages Feb 12.
When can I plant tomatoes in Seattle, Washington?
Tomatoes are a very tender crop, so the Colorado State Extension rule puts them out 2 or more weeks after the last spring frost: Mar 22 – Apr 5 in Seattle, Washington. Start the seeds indoors Feb 1 – Mar 1, which is 5 to 7 weeks before that transplant window.
How long is the growing season in Seattle, Washington?
Seattle, Washington averages 258 frost-free days, between the 50% last spring frost on Mar 8 and the 50% first fall frost on Nov 21 at SEATTLE TACOMA INTERNATIONAL AIRPORT, WA US. Check a variety's days to harvest against that number before buying seed.
When should I start seeds indoors in Seattle, Washington?
The earliest indoor sowing on this calendar is broccoli and cabbage at Dec 21 – Jan 18. Hardy crops are transplanted out Feb 8 – Feb 22 here, and each crop's indoor window is simply its outdoor window minus the transplant age published by Colorado State Extension, so nothing starts earlier than that.
What can I plant in fall in Seattle, Washington?
The crops with a separate fall sowing here, latest first, are radishes, spinach, kohlrabi, turnips, lettuce (leaf) and onions (green), plus 21 more on the chart above. Each fall date counts the crop's days to harvest back from the first fall frost on Nov 21, plus an allowance for frost-tolerant crops that is our own assumption, not the source's.
Station data and limitations
| NOAA station | SEATTLE TACOMA INTERNATIONAL AIRPORT, WA US (USW00024233) |
|---|---|
| Location | 47.4444, -122.3138 · elevation 112.8 m |
| Last spring 32°F / 28°F (50%) | Mar 8 / Feb 12 |
| First fall 32°F / 28°F (50%) | Nov 21 / Dec 9 |
| Dataset | NOAA/NCEI U.S. Climate Normals 1991–2020, annual/seasonal product, data types ANN-TMIN-PRBLST/PRBFST-T32FP50 and T28FP50 |
| Retrieved | 2026-10-16 |
The normals describe the airport station, not your yard. They are averages of a 30-year record and say nothing about this year's weather. Watch the local forecast around the dates shown, and use soil temperature for warm-season crops, which the Colorado State guide treats as the better signal.
Nearby calendars
- Portland, Oregon — last spring frost Mar 16
- Sacramento, California — last spring frost Feb 9
- Salt Lake City, Utah — last spring frost Apr 21
- Los Angeles, California
Read the method behind these dates: last frost date vs hardiness zone.