Frost Dates & Planting Calendar for Tukwila, WA
Plan your garden around Tukwila, 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 13
Safe Mar 31
Typical Mar 13
Risky Feb 19
First Fall Frost
November 16
Safe Oct 29
Typical Nov 16
Risky Dec 9
Growing Season
248 days
Typical last frost to typical first frost.
USDA Hardiness Zone
Zone 9a
Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.
Data: NOAA station RENTON MUNI AP, WA US, 4.1 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 16 – Jan 30 | — | Mar 20 – Mar 27 | — | 60–85 days | Start indoors 6-8 weeks before last frost; transplant out 1-2 weeks after last frost once soil has warmed. |
| Pepper | Jan 2 – Jan 16 | — | Mar 20 – Apr 3 | — | 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 | Jan 2 – Jan 16 | — | Mar 27 – Apr 3 | — | 65–85 days | Warm-season crop, similar timing to pepper; needs consistently warm soil (65F+) to transplant. |
| Cucumber | Feb 13 – Feb 20 | Mar 20 – Mar 27 | Mar 20 – Mar 27 | — | 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 20 – Feb 27 | Mar 20 – Apr 3 | Mar 20 – Mar 27 | — | 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 13 – Feb 20 | Mar 20 – Apr 3 | Mar 20 – Mar 27 | — | 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 20 – Apr 3 | — | — | 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 13 – Feb 20 | — | Mar 27 – Apr 3 | — | 70–90 days | Needs warm soil (65F+); start indoors 3-4 weeks before last frost, transplant 2-3 weeks after last frost. |
| Cantaloupe | Feb 13 – Feb 20 | — | Mar 27 – Apr 3 | — | 70–90 days | Same warm-soil requirements as watermelon; avoid disturbing roots when transplanting. |
| Corn | — | Mar 13 – Mar 27 | — | — | 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 13 – Mar 27 | — | — | 50–65 days | Direct sow at last frost to 2 weeks after, once soil has warmed; frost-tender, do not rush. |
| Pea | — | Jan 30 – Feb 13 | — | — | 55–70 days | Cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Lettuce | — | Feb 13 – Feb 27 | — | Sep 21 – Oct 5 | 45–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. Also transplantable from indoor starts. |
| Spinach | — | Jan 30 – Feb 13 | — | Sep 21 – Oct 5 | 40–50 days | Very cold-hardy; direct sow 4-6 weeks before last frost as soon as soil can be worked. |
| Kale | — | Feb 13 – Feb 27 | — | Sep 7 – Sep 21 | 50–65 days | Cold-hardy; direct sow 2-4 weeks before last frost or start indoors for earlier transplants. |
| Arugula | — | Feb 13 – Feb 27 | — | Oct 5 – Oct 12 | 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 20 – Mar 6 | — | — | 50–60 days | Fairly cold-hardy; direct sow 1-3 weeks before last frost. Tolerates light frost in fall too. |
| Broccoli | Jan 23 – Feb 6 | — | Feb 20 – Feb 27 | Sep 14 – Sep 21 | 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 23 – Feb 6 | — | Feb 27 – Mar 6 | Sep 7 – Sep 14 | 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 23 – Feb 6 | — | Feb 13 – Feb 27 | Sep 7 – Sep 21 | 60–100 days | Cold-hardy; start indoors 5-7 weeks before last frost, transplant 2-4 weeks before last frost. |
| Brussels Sprouts | Jan 23 – Feb 6 | — | Feb 20 – Mar 6 | — | 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 13 – Feb 27 | — | Aug 24 – Sep 7 | 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 13 – Feb 27 | — | Sep 7 – Sep 21 | 50–65 days | Direct sow 2-4 weeks before last frost; tolerates light frost. |
| Radish | — | Feb 6 – Feb 20 | — | Oct 5 – Oct 19 | 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 13 – Feb 27 | — | Sep 7 – Sep 21 | 40–60 days | Cold-hardy; direct sow 2-4 weeks before last frost. |
| Onion | Jan 2 – Jan 16 | — | Feb 13 – Feb 27 | — | 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 19 – Nov 2 | 240–270 days | Fall-planted crop only; not planted in spring in most climates. |
| Potato | — | Feb 13 – Feb 27 | — | — | 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 27 – Apr 10 | — | 90–120 days | Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive. |
| Asparagus | — | — | Feb 13 – Feb 27 | — | 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 30 – Feb 6 | — | Mar 20 – Mar 27 | — | 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 20 – Mar 6 | — | Sep 21 – Oct 5 | 45–70 days | Cool-season, bolts in heat; direct sow 1-3 weeks before last frost, succession sow through spring. |
| Parsley | Jan 16 – Jan 30 | — | Feb 27 – Mar 6 | — | 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 20 – Mar 6 | — | — | 40–60 days | Taprooted, does not transplant well; direct sow 1-3 weeks before last frost, succession sow through summer. |
| Oregano | Jan 16 – Jan 30 | — | Mar 13 – Mar 20 | — | 80–90 days | Perennial herb; start indoors 6-8 weeks before last frost, transplant around/just after last frost date. |
| Thyme | Jan 16 – Jan 30 | — | Mar 13 – Mar 20 | — | 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 20 – Apr 3 | — | — | 70–100 days | Direct sow 1-3 weeks after last frost once soil has warmed; taprooted, resents transplanting. |
| Zinnia | Feb 13 – Feb 20 | Mar 20 – Apr 3 | Mar 20 – Mar 27 | — | 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 30 – Feb 13 | — | Mar 20 – Mar 27 | — | 45–60 days | Frost-tender; start indoors 4-6 weeks before last frost, transplant after all frost danger has passed. |
| Cosmos | Feb 13 – Feb 20 | Mar 20 – Apr 3 | Mar 20 – Mar 27 | — | 60–90 days | Easy from direct seed 1-3 weeks after last frost; can also start indoors 3-4 weeks early. |
| Nasturtium | — | Mar 20 – Apr 3 | — | — | 50–65 days | Frost-tender, resents root disturbance; direct sow 1-3 weeks after last frost once soil has warmed. |
| Dahlia | — | — | Mar 20 – Apr 3 | — | 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 Tukwila, WA?
Based on 1991–2020 NOAA climate normals for the RENTON MUNI AP, WA US station, the last spring frost in Tukwila typically falls around March 13. A cautious gardener might wait until March 31 (only a 10% chance of a later frost), while February 19 marks an earlier, higher-risk planting date.
When is the first frost in Tukwila, WA in fall?
The first fall frost in Tukwila typically arrives around November 16. To stay safe, assume frost could start as early as October 29; in milder years it can hold off until December 9.
How long is the growing season in Tukwila, WA?
Tukwila's average frost-free growing season is about 248 days, running from the typical last spring frost (March 13) to the typical first fall frost (November 16).
What USDA hardiness zone is Tukwila, WA in?
Tukwila, WA is in USDA plant hardiness zone 9a, per the USDA's 2023 Plant Hardiness Zone Map. Subtropical to frost-free — heat, not cold, is the main limit on what you can grow.