When to plant in Alderwood Manor, WA
USDA Zone 9aAlderwood Manor, Washington frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
A generous ~253-day season lets Alderwood Manor gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. Zone 9a is warm enough that Alderwood Manor can grow subtropical perennials, and the short (or absent) frost period barely limits the annual calendar.
Frost probability
EVERETT SNOHOMISH 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 Alderwood Manor’s own odds, recorded at EVERETT SNOHOMISH AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 27 | Apr 3 | Mar 15 | Oct 19 | Nov 2 | Nov 20 |
| 32°F | Mar 29 | Mar 9 | Feb 15 | Oct 31 | Nov 17 | Dec 7 |
| 28°F | Mar 9 | Feb 13 | Jan 1 | Nov 15 | Dec 6 | Jan 8 |
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 Alderwood Manor, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 19 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.
Alderwood Manor planting FAQ
When is the last spring frost in Alderwood Manor, WA?
Alderwood Manor's average last spring frost falls near March 9 — the 50% mark at 32°F in the 1991–2020 normals. Hold tender transplants until the risk has passed, then plant out.
When is the first fall frost in Alderwood Manor, WA?
In Alderwood Manor, the first 32°F freeze of fall lands around November 17 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Alderwood Manor in?
Alderwood Manor is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Alderwood Manor?
There are roughly 253 frost-free days in Alderwood Manor (a long growing season), running from the average last frost around March 9 to the first fall frost near November 17.
When should I plant tomatoes in Alderwood Manor?
In Alderwood Manor, start tomato seeds indoors around January 12–January 26, then transplant seedlings outdoors around March 16 once the danger of frost has passed.
Never miss a window in Alderwood Manor
An email when it’s time to start seeds, transplant, and sow — timed to Alderwood Manor’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Bothell West · 2 km
- Lynnwood · 3 km
- Mountlake Terrace · 3 km
- Martha Lake · 4 km
- North Lynnwood · 4 km
- Bothell East · 6 km
- Mill Creek East · 6 km
- Edmonds · 6 km
Frost dates recorded at EVERETT SNOHOMISH AP, 10 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 Alderwood Manor, WA — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00024222. Retrieved from https://blissgarden.com/washington/alderwood-manor.