In Seattle, the average last spring frost is Mar 15 and the average first fall frost is Nov 15, a growing season of about 245 days (zone 9a). Start tomatoes indoors around Feb 1 and move them outside from Mar 29. For a fall and winter garden, sow peas and kale around Sep 6, lettuce around Sep 20, spinach around Sep 27 and radishes around Oct 11.
Seattle at a glance
- Last spring frost
- Mar 15 (average)
- First fall frost
- Nov 15 (average)
- Frost-free season
- About 245 days
- Hardiness zone
- 9a (USDA)
- Weather stations
- Seattle Boeing Fld, WA; Seattle Sand Pt WSFO, WA; and Kent, WA, 1991 to 2020 normals. GrowSmart's dates are the median of these stations, to within 3 days
An average frost date means frost is still possible after it in about half of years. GrowSmart times tender crops like tomatoes, peppers and basil after this date, not on it.
What to plant in Seattle this month (January)
- Start onions indoors: Jan 4
Coming up in early February: start tomatoes indoors (Feb 1), start peppers indoors (Feb 1), start eggplant indoors (Feb 1), start lettuce indoors (Feb 1), start kale indoors (Feb 8), start broccoli indoors (Feb 8) and start cabbage indoors (Feb 8).
What to plant in Seattle this month (February)
- Start tomatoes indoors: Feb 1
- Start peppers indoors: Feb 1
- Start eggplant indoors: Feb 1
- Start lettuce indoors: Feb 1
- Start kale indoors: Feb 8
- Start broccoli indoors: Feb 8
- Start cabbage indoors: Feb 8
- Start basil indoors: Feb 15
- Direct sow spinach: Feb 22
- Direct sow peas: Feb 22
- Direct sow radishes: Feb 22
Coming up in early March: transplant lettuce (Mar 1), direct sow carrots (Mar 1), start cucumbers indoors (Mar 1), start zucchini indoors (Mar 1), start winter squash indoors (Mar 1), direct sow beets (Mar 8), transplant kale (Mar 8), transplant broccoli (Mar 8), transplant cabbage (Mar 8) and direct sow potatoes (Mar 8).
What to plant in Seattle this month (March)
- Transplant lettuce: Mar 1
- Direct sow carrots: Mar 1
- Start cucumbers indoors: Mar 1
- Start zucchini indoors: Mar 1
- Start winter squash indoors: Mar 1
- Direct sow beets: Mar 8
- Transplant kale: Mar 8
- Transplant broccoli: Mar 8
- Transplant cabbage: Mar 8
- Direct sow potatoes: Mar 8
- Transplant onions: Mar 15
- Transplant cucumbers: Mar 22
- Transplant zucchini: Mar 22
- Transplant winter squash: Mar 22
- Direct sow beans: Mar 22
- Transplant tomatoes: Mar 29
- Transplant peppers: Mar 29
- Transplant eggplant: Mar 29
- Transplant basil: Mar 29
What to plant in Seattle this month (April)
Nothing is scheduled to be sown or planted in Seattle in April. Next up: sow peas for a fall harvest on Sep 6.
What to plant in Seattle this month (May)
Nothing is scheduled to be sown or planted in Seattle in May. Next up: sow peas for a fall harvest on Sep 6.
What to plant in Seattle this month (June)
Nothing is scheduled to be sown or planted in Seattle in June. Next up: sow peas for a fall harvest on Sep 6.
What to plant in Seattle this month (July)
Nothing is scheduled to be sown or planted in Seattle in July. Next up: sow peas for a fall harvest on Sep 6.
What to plant in Seattle this month (August)
Nothing is scheduled to be sown or planted in Seattle in August. Next up: sow peas for a fall harvest on Sep 6.
What to plant in Seattle this month (September)
- Sow peas for a fall harvest: Sep 6
- Sow kale for a fall harvest: Sep 6
- Sow lettuce for a fall harvest: Sep 20
- Sow spinach for a fall harvest: Sep 27
Coming up in early October: sow radishes for a fall harvest (Oct 11).
What to plant in Seattle this month (October)
- Sow radishes for a fall harvest: Oct 11
What to plant in Seattle this month (November)
- Plant garlic: Nov 22 to Nov 29
What to plant in Seattle this month (December)
Nothing is scheduled to be sown or planted in Seattle in December. Next up: start onions indoors on Jan 4.
Seattle planting calendar
| Crop | Start indoors | Plant outside | Harvest |
|---|---|---|---|
| Tomatoes | Feb 1 | Transplant Mar 29 | From Jun 15 |
| Peppers | Feb 1 | Transplant Mar 29 | From Jun 9 |
| Eggplant | Feb 1 | Transplant Mar 29 | From Jun 12 |
| Basil | Feb 15 | Transplant Mar 29 | From May 10 |
| Onions (from seed) | Jan 4 | Transplant Mar 15 | From Jun 23 |
| Lettuce | Feb 1 | Transplant Mar 1Fall: direct sow Sep 20 | From Apr 10Fall: from Oct 30 |
| Spinach | n/a | Direct sow Feb 22Fall: direct sow Sep 27 | From Apr 3Fall: from Nov 6 |
| Peas | n/a | Direct sow Feb 22Fall: direct sow Sep 6 | From Apr 23Fall: from Nov 5 |
| Radishes | n/a | Direct sow Feb 22Fall: direct sow Oct 11 | From Mar 19Fall: from Nov 5 |
| Carrots | n/a | Direct sow Mar 1 | From May 10 |
| Beets | n/a | Direct sow Mar 8 | From May 2 |
| Kale | Feb 8 | Transplant Mar 8Fall: direct sow Sep 6 | From May 2Fall: from Oct 31 |
| Broccoli | Feb 8 | Transplant Mar 8 | From May 12 |
| Cabbage | Feb 8 | Transplant Mar 8 | From May 17 |
| Cucumbers | Mar 1 | Transplant Mar 22 | From May 16 |
| Zucchini | Mar 1 | Transplant Mar 22 | From May 11 |
| Winter squash | Mar 1 | Transplant Mar 22 | From Jun 20 |
| Beans | n/a | Direct sow Mar 22 | From May 16 |
| Potatoes | n/a | Direct sow Mar 8 | From May 27 |
| Garlic | n/a | Plant cloves Nov 22 to Nov 29 | Around Jun 7 the next year |
Dates are for one planting of each crop, from Seattle's average frost dates. Tomatoes are indeterminate, lettuce is looseleaf and beans are bush beans. Harvest dates are when the first picking is usually ready. Garlic follows University of Minnesota Extension (see below).
Fall planting in Seattle
Plant garlic Nov 22 to Nov 29. That is one to two weeks after Seattle's average first fall frost of Nov 15, the timing University of Minnesota Extension recommends, so the cloves root before winter without sending shoots up. Harvest comes around Jun 7 the following summer.
Shallots: GrowSmart's plan has you plant shallot sets in fall in zone 5 and warmer, and in spring in colder zones.
Cool-season crops GrowSmart schedules for a fall harvest in Seattle:
- Peas: sow Sep 6, ready from about Nov 5
- Kale: sow Sep 6, ready from about Oct 31
- Lettuce: sow Sep 20, ready from about Oct 30
- Spinach: sow Sep 27, ready from about Nov 6
- Radishes: sow Oct 11, ready from about Nov 5
Nearby planting calendars
Seattle planting questions
When is the last frost in Seattle?
The average last spring frost in Seattle is Mar 15, and the average first fall frost is Nov 15, from 1991 to 2020 climate normals at 3 nearby weather stations. Frost is still possible after the spring date in about half of years.
When should I start tomato seeds in Seattle?
Start tomatoes indoors around Feb 1, 8 weeks before moving them outside around Mar 29, which is two weeks after the average last frost.
What can I plant in Seattle in fall?
Fall and winter is a main growing season in Seattle. Sow peas and kale around Sep 6, lettuce around Sep 20, spinach around Sep 27 and radishes around Oct 11, and plant garlic around Nov 22.