When to Plant Sweet Corn in Washington
In Washington, the time to sow sweet corn outside runs from Mar 9 – Mar 23 in Burien to May 13 – May 27 in Pullman. In Seattle, it's Mar 15 – Mar 29. The average last spring frost differs by about 9 weeks across the state (Mar 2 in Burien, May 6 in Pullman), so use the dates for the town nearest you.
Sow corn in blocks rather than single rows so it pollinates well. Wait for soil around 60°F.
- Sow outside: 1–3 weeks after the last frost.
Sweet Corn planting dates in Washington by city
| City | Zone | Sow outside |
|---|---|---|
| Auburn | 8b | Mar 27 – Apr 10 |
| Bellevue | 9a | Mar 15 – Mar 29 |
| Bellingham | 8b | Apr 8 – Apr 22 |
| Bothell | 8b | Mar 15 – Mar 29 |
| Bremerton | 8b | Apr 5 – Apr 19 |
| Burien | 9a | Mar 9 – Mar 23 |
| Des Moines | 9a | Mar 9 – Mar 23 |
| Edmonds | 9a | Mar 16 – Mar 30 |
| Everett | 8b | Mar 31 – Apr 14 |
| Federal Way | 8b | Mar 15 – Mar 29 |
| Issaquah | 8b | Mar 20 – Apr 3 |
| Kennewick | 7b | Apr 4 – Apr 18 |
| Kent | 8b | Mar 27 – Apr 10 |
| Kirkland | 9a | Mar 15 – Mar 29 |
| Lacey | 8b | May 6 – May 20 |
| Lake Stevens | 8b | Mar 31 – Apr 14 |
| Lakewood | 8b | Mar 18 – Apr 1 |
| Longview | 8b | Apr 15 – Apr 29 |
| Lynnwood | 9a | Mar 16 – Mar 30 |
| Marysville | 8b | Mar 31 – Apr 14 |
| Mount Vernon | 8b | Mar 31 – Apr 14 |
| Olympia | 8b | May 6 – May 20 |
| Pasco | 7b | May 4 – May 18 |
| Pullman | 6b | May 13 – May 27 |
| Puyallup | 8b | Apr 18 – May 2 |
| Redmond | 8b | Mar 15 – Mar 29 |
| Renton | 9a | Mar 20 – Apr 3 |
| Richland | 7b | Apr 13 – Apr 27 |
| Sammamish | 8b | Apr 6 – Apr 20 |
| SeaTac | 9a | Mar 9 – Mar 23 |
| Seattle | 9a | Mar 15 – Mar 29 |
| Shoreline | 9a | Mar 15 – Mar 29 |
| Spokane | 7a | May 3 – May 17 |
| Spokane Valley | 7a | May 3 – May 17 |
| Tacoma | 8b | Mar 15 – Mar 29 |
| University Place | 8b | Mar 18 – Apr 1 |
| Vancouver | 8b | Apr 5 – Apr 19 |
| Walla Walla | 7a | Apr 3 – Apr 17 |
| Wenatchee | 7a | Apr 11 – Apr 25 |
| Yakima | 7a | Apr 15 – Apr 29 |
Calculated from each town's average (50%) frost dates, from the nearest NOAA station (1991–2020). Typical dates for the 2027 planting season, based on NOAA's 1991–2020 averages. They are long-term odds, not a forecast: always check your local forecast before planting. Zones: 2023 USDA Plant Hardiness Zone Map (USDA-ARS and Oregon State University). Not the official map; see planthardiness.ars.usda.gov.
See all frost dates in Washington, or the general guide to when to plant sweet corn.
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