When to plant in Walla Walla, WA
USDA Zone 7aHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Walla Walla, Washington — all computed from Walla Walla's nearest NOAA weather station.
Zone 7a means many perennials and even some tender shrubs overwinter in Walla Walla, while your frost dates still decide when annuals go out.
Frost probability
WALLA WALLA RGNL 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 Walla Walla’s own odds, recorded at WALLA WALLA RGNL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 8 | Apr 21 | Apr 2 | Oct 4 | Oct 19 | Nov 2 |
| 32°F | Apr 22 | Mar 27 | Mar 3 | Oct 15 | Oct 31 | Nov 17 |
| 28°F | Mar 27 | Mar 4 | Feb 9 | Oct 25 | Nov 14 | Dec 4 |
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 Walla Walla, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 15 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.
Walla Walla planting FAQ
When is the last spring frost in Walla Walla, WA?
Plan for the last spring frost in Walla Walla around March 27 (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 Walla Walla, WA?
The first fall frost in Walla Walla typically arrives around October 31 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Walla Walla in?
Walla Walla is in USDA hardiness zone 7a. In zone 7a, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Walla Walla?
There are roughly 218 frost-free days in Walla Walla (a long growing season), running from the average last frost around March 27 to the first fall frost near October 31.
When should I plant tomatoes in Walla Walla?
In Walla Walla, start tomato seeds indoors around January 30–February 13, then transplant seedlings outdoors around April 3 once the danger of frost has passed.
Never miss a window in Walla Walla
An email when it’s time to start seeds, transplant, and sow — timed to Walla Walla’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at WALLA WALLA RGNL AP, 5 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 Walla Walla, WA — Frost Dates & Zone 7a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00024160. Retrieved from https://blissgarden.com/washington/walla-walla.