When to plant in Des Moines, WA
USDA Zone 9aEverything below — frost dates, hardiness zone, and what to plant when in Des Moines, Washington — is derived from the closest NOAA station with complete climate normals.
With about 266 frost-free days, Des Moines supports back-to-back plantings; stagger sowings every few weeks to keep beds productive spring through fall. In zone 9a, frost is a minor factor for Des Moines — most perennials thrive, and annual vegetables can go out early and stay late.
The average last spring frost in Des Moines is now 6 days earlier than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
SEATTLE TACOMA INTL AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Des Moines’s own odds, recorded at SEATTLE TACOMA INTL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 21 | Mar 31 | Mar 13 | Oct 24 | Nov 7 | Nov 23 |
| 32°F | Mar 23 | Mar 2 | Feb 5 | Nov 6 | Nov 23 | Dec 15 |
| 28°F | Feb 28 | Feb 4 | Dec 20 | Nov 17 | Dec 10 | Jan 16 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Des Moines, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 14 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Des Moines planting FAQ
When is the last spring frost in Des Moines, WA?
Plan for the last spring frost in Des Moines around March 2 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Des Moines, WA?
Expect Des Moines's first fall frost near November 23 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Des Moines in?
Des Moines is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Des Moines?
Des Moines has about 266 frost-free days — a long growing season — between the average last spring frost (March 2) and first fall frost (November 23).
When should I plant tomatoes in Des Moines?
For Des Moines, sow tomatoes indoors about January 5–January 19 and move the seedlings out around March 9, after the last spring frost.
Never miss a window in Des Moines
An email when it’s time to start seeds, transplant, and sow — timed to Des Moines’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- SeaTac · 6 km
- Lakeland North · 6 km
- Kent · 8 km
- Federal Way · 9 km
- Burien · 10 km
- Tukwila · 10 km
- Auburn · 12 km
- Lakeland South · 13 km
Frost dates recorded at SEATTLE TACOMA INTL AP, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Des Moines, WA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00024233. Retrieved from https://blissgarden.com/washington/des-moines.