When to plant in Oak Grove, OR
USDA Zone 9aEverything below — frost dates, hardiness zone, and what to plant when in Oak Grove, Oregon — is derived from the closest NOAA station with complete climate normals.
A generous ~245-day season lets Oak Grove gardeners direct-sow more and still ripen long-maturity crops like melons and winter squash. In zone 9a, frost is a minor factor for Oak Grove — most perennials thrive, and annual vegetables can go out early and stay late.
Frost probability
OREGON CITY · 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 Oak Grove’s own odds, recorded at OREGON CITY.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 4 | Apr 15 | Mar 26 | Oct 16 | Oct 31 | Nov 20 |
| 32°F | Apr 11 | Mar 18 | Feb 19 | Oct 30 | Nov 18 | Dec 12 |
| 28°F | Mar 7 | Feb 12 | Jan 1 | Nov 16 | Dec 8 | Jan 5 |
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 Oak Grove, 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.
Oak Grove planting FAQ
When is the last spring frost in Oak Grove, OR?
Plan for the last spring frost in Oak Grove around March 18 (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 Oak Grove, OR?
Expect Oak Grove's first fall frost near November 18 — a 50% chance of 32°F by that date. Bring in or cover tender crops ahead of it.
What hardiness zone is Oak Grove in?
Oak Grove is in USDA hardiness zone 9a. In zone 9a, winters are mild — many tender perennials overwinter here.
How long is the growing season in Oak Grove?
Oak Grove has about 245 frost-free days — a long growing season — between the average last spring frost (March 18) and first fall frost (November 18).
When should I plant tomatoes in Oak Grove?
For Oak Grove, sow tomatoes indoors about January 21–February 4 and move the seedlings out around March 25, after the last spring frost.
Never miss a window in Oak Grove
An email when it’s time to start seeds, transplant, and sow — timed to Oak Grove’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Oatfield · 3 km
- Milwaukie · 4 km
- Gladstone · 4 km
- Lake Oswego · 5 km
- West Linn · 5 km
- Oregon City · 9 km
- Happy Valley · 10 km
- Tualatin · 12 km
Frost dates recorded at OREGON CITY, 7 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 Oak Grove, OR — Frost Dates & Zone 9a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00356334. Retrieved from https://blissgarden.com/oregon/oak-grove.