Frost Dates & Planting Calendar for Bothell, WA
Plan your garden around Bothell, WA's typical frost-free growing season, using NOAA climate normals and a 42-crop planting calendar built for this location.
Last Spring Frost
March 8
Safe Mar 29
Typical Mar 8
Risky Feb 13
First Fall Frost
November 23
Safe Nov 4
Typical Nov 23
Risky Dec 16
Growing Season
259 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 8b
Mild winters and a long growing season, room for both cool- and warm-season crops.
Data: NOAA station SEATTLE SAND PT WSFO, WA US, 9.1 km away.
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days until the typical last spring frost
Monthly Temperatures
Avg. high
Avg. temp
Avg. low
Planting Calendar
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Tomato | Jan 11 – Jan 25 | — | Mar 15 – Mar 22 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Dec 28 – Jan 11 | — | Mar 15 – Mar 29 | — | 60–90 days | Slow to germinate; start indoors 8-10 weeks before last frost. Transplant only once nights stay above 55F, 1-3 weeks after last frost. |
| Eggplant | Dec 28 – Jan 11 | — | Mar 22 – Mar 29 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Feb 8 – Feb 15 | Mar 15 – Mar 22 | Mar 15 – Mar 22 | — | 50–65 days | Can be started indoors 3-4 weeks before transplanting, or direct-sown 1-2 weeks after last frost once soil is warm. |
| Zucchini | Feb 15 – Feb 22 | Mar 15 – Mar 29 | Mar 15 – Mar 22 | — | 45–55 days | Fast-growing squash; direct sow 1-3 weeks after last frost, or start indoors 2-3 weeks early for a head start. |
| Winter Squash | Feb 8 – Feb 15 | Mar 15 – Mar 29 | Mar 15 – Mar 22 | — | 80–110 days | Long season; direct sow after soil warms, or start indoors 3-4 weeks before last frost in short-season climates. |
| Pumpkin | — | Mar 15 – Mar 29 | — | — | 90–120 days | Direct sow 1-3 weeks after last frost; back-time from your first fall frost so the 90-120 day maturity window lands before it. |
| Watermelon | Feb 8 – Feb 15 | — | Mar 22 – Mar 29 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Feb 8 – Feb 15 | — | Mar 22 – Mar 29 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Mar 8 – Mar 22 | — | — | 60–100 days | Direct sow at last frost to 2 weeks after, once soil reaches 60F; does not transplant well. Succession sow every 2 weeks. |
| Green Bean | — | Mar 8 – Mar 22 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Jan 25 – Feb 8 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Feb 8 – Feb 22 | — | Sep 28 – Oct 12 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Jan 25 – Feb 8 | — | Sep 28 – Oct 12 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Feb 8 – Feb 22 | — | Sep 14 – Sep 28 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Feb 8 – Feb 22 | — | Oct 12 – Oct 19 | 30–40 days | Fast-growing, cold-tolerant green; direct sow 2-4 weeks before last frost, succession sow every 2-3 weeks. |
| Swiss Chard | — | Feb 15 – Mar 1 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Jan 18 – Feb 1 | — | Feb 15 – Feb 22 | Sep 21 – Sep 28 | 55–80 days | Start indoors 5-7 weeks before last frost; transplant out 2-3 weeks before last frost (hardens off to light frost). |
| Cauliflower | Jan 18 – Feb 1 | — | Feb 22 – Mar 1 | Sep 14 – Sep 21 | 55–85 days | Fussier than broccoli about temperature swings; start indoors 5-7 weeks before last frost, transplant 1-2 weeks before last frost. |
| Cabbage | Jan 18 – Feb 1 | — | Feb 8 – Feb 22 | Sep 14 – Sep 28 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Jan 18 – Feb 1 | — | Feb 15 – Mar 1 | — | 90–110 days | Long-season crop best timed to mature after a light fall frost for sweetest flavor; start indoors 5-7 weeks before last frost. |
| Carrot | — | Feb 8 – Feb 22 | — | Aug 31 – Sep 14 | 60–80 days | Direct sow only (does not transplant); sow 2-4 weeks before last frost, as soon as soil can be worked. |
| Beet | — | Feb 8 – Feb 22 | — | Sep 14 – Sep 28 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Feb 1 – Feb 15 | — | Oct 12 – Oct 26 | 22–30 days | Very fast and cold-hardy; direct sow 3-5 weeks before last frost, as soon as soil can be worked. |
| Turnip | — | Feb 8 – Feb 22 | — | Sep 14 – Sep 28 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Dec 28 – Jan 11 | — | Feb 8 – Feb 22 | — | 90–120 days | Start seeds indoors 8-10 weeks before last frost (or use sets/transplants); set out 2-4 weeks before last frost, very cold-tolerant as seedlings. |
| Garlic | — | — | — | Oct 26 – Nov 9 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Feb 8 – Feb 22 | — | — | 70–120 days | Plant seed potatoes 2-4 weeks before last frost, as soon as soil can be worked and is above 45F; light frost on emerging foliage is usually tolerated. |
| Sweet Potato | — | — | Mar 22 – Apr 5 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Feb 8 – Feb 22 | — | 730–1095 days | Perennial; plant crowns 2-4 weeks before last frost as soon as soil can be worked. Takes 2-3 years to full production. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Basil | Jan 25 – Feb 1 | — | Mar 15 – Mar 22 | — | 50–70 days | Very frost/cold sensitive; start indoors 5-6 weeks before last frost, transplant only after all danger of frost (1-2 weeks after) and nights stay warm. |
| Cilantro | — | Feb 15 – Mar 1 | — | Sep 28 – Oct 12 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Jan 11 – Jan 25 | — | Feb 22 – Mar 1 | — | 70–90 days | Slow to germinate; start indoors 6-8 weeks before last frost, transplant 1-2 weeks before last frost (biennial, cold-tolerant). |
| Dill | — | Feb 15 – Mar 1 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Jan 11 – Jan 25 | — | Mar 8 – Mar 15 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Jan 11 – Jan 25 | — | Mar 8 – Mar 15 | — | 85–95 days | Perennial herb, slow from seed; start indoors 6-8 weeks before last frost, transplant around/after last frost. |
| Crop | Start indoors | Direct sow | Transplant | Fall planting | Maturity | Notes |
|---|---|---|---|---|---|---|
| Sunflower | — | Mar 15 – Mar 29 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Feb 8 – Feb 15 | Mar 15 – Mar 29 | Mar 15 – Mar 22 | — | 60–70 days | Frost-tender; direct sow 1-3 weeks after last frost, or start indoors 3-4 weeks early for earlier blooms. |
| Marigold | Jan 25 – Feb 8 | — | Mar 15 – Mar 22 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Feb 8 – Feb 15 | Mar 15 – Mar 29 | Mar 15 – Mar 22 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Mar 15 – Mar 29 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Mar 15 – Mar 29 | — | 90–120 days | Plant tubers 1-3 weeks after last frost once soil is warm (60F+); very frost-sensitive. |
Date ranges are estimates based on university extension guidelines and this city's NOAA frost normals — not a guarantee. Scroll to see all columns on narrow screens.
Frequently Asked Questions
When is the last frost in Bothell, WA?
Based on 1991–2020 NOAA climate normals for the SEATTLE SAND PT WSFO, WA US station, the last spring frost in Bothell typically falls around March 8. A cautious gardener might wait until March 29 (only a 10% chance of a later frost), while February 13 marks an earlier, higher-risk planting date.
When is the first frost in Bothell, WA in fall?
The first fall frost in Bothell typically arrives around November 23. To stay safe, assume frost could start as early as November 4; in milder years it can hold off until December 16.
How long is the growing season in Bothell, WA?
Bothell's average frost-free growing season is about 259 days, running from the typical last spring frost (March 8) to the typical first fall frost (November 23).
What USDA hardiness zone is Bothell, WA in?
Bothell, WA is in USDA plant hardiness zone 8b, per the USDA's 2023 Plant Hardiness Zone Map. Mild winters and a long growing season, room for both cool- and warm-season crops.