Last frost date in Lake Oswego, Oregon
March 18
Average last frost in spring. In an early year (1 in 10) it's over by February 19; in a late year (1 in 10) it comes after April 11.
November 18
Average first frost in fall. 1 year in 10 it comes by October 30.
Source: NOAA U.S. Climate Normals 1991–2020, station Oregon City (USC00356334), 6.1 miles from Lake Oswego, elevation 167 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Feb 19 | Mar 18 | Apr 11 |
| First frost in fall | Oct 30 | Nov 18 | Dec 12 |
An early or late year is one in 10: 1 year in 10 the frost comes before the early date, and 1 year in 10 after the late date.
Frost-free days in an average year: 244
Planting calendar for Lake Oswego
Fall planting
USDA dates for places whose average first freeze is about November 20 (Lake Oswego: November 18).
- CucumbersJune 1 – Aug 15 (past for this year)
- Eggplant plantsJune 1 – Aug 1 (past for this year)
- New Zealand spinachJune 1 – Aug 15 (past for this year)
- OkraJune 1 – Sept 10 (past for this year)
- Peppers plantsJune 1 – Aug 15 (past for this year)
- SoybeansJune 1 – July 30 (past for this year)
- Summer squashJune 1 – Aug 20 (past for this year)
- Sweet cornJune 1 – Sept 1 (past for this year)
- Sweet potatoesJune 1 – July 1 (past for this year)
- Swiss chardJune 1 – Oct 1 (past for this year)
- TomatoesJune 1 – Aug 1 (past for this year)
- Black-eyed peasJuly 1 – Sept 1 (past for this year)
- Snap beansJuly 1 – Sept 10 (past for this year)
- Winter squashJuly 1 – Aug 1 (past for this year)
- Celery and celeriac plantsJuly 15 – Sept 1 (past for this year)
- Lima beansJuly 15 – Sept 1 (past for this year)
- SalsifyJuly 15 – Aug 15 (past for this year)
- Witloof chicoryJuly 20 – Sept 1 (past for this year)
- Broccoli plantsAug 1 – Sept 15 (past for this year)
- Brussels sprouts plantsAug 1 – Sept 15 (past for this year)
- Cauliflower plantsAug 1 – Sept 15 (past for this year)
- ParsnipsAug 1 – Sept 1 (past for this year)
- RutabagaAug 1 – Sept 1 (past for this year)
- PotatoesAug 10 – Sept 15 (past for this year)
- Florence fennelAug 15 – Sept 15 (past for this year)
- GarlicAug 15 – Oct 1 (past for this year)
- KaleAug 15 – Oct 15 (past for this year)
- ShallotsAug 15 – Oct 1 (past for this year)
- SorrelAug 15 – Oct 15 (past for this year)
- Collards plantsAug 25 – Nov 1Now
- BeetsSept 1 – Dec 1Now
- Cabbage plantsSept 1 – Dec 1Now
- CarrotsSept 1 – Nov 1Now
- Chinese cabbageSept 1 – Oct 15 (past for this year)
- DandelionSept 1 – Nov 1Now
- EndiveSept 1 – Oct 1 (past for this year)
- Head lettuce plantsSept 1 – Nov 1Now
- KohlrabiSept 1 – Oct 15 (past for this year)
- Leaf lettuceSept 1 – Nov 1Now
- LeeksSept 1 – Nov 1Now
- Mustard greensSept 1 – Dec 1Now
- Onion seedSept 1 – Nov 1Now
- ParsleySept 1 – Dec 31Now
- RadishesSept 1 – Dec 1Now
- TurnipsSept 1 – Nov 15Now
- Corn saladOct 1 – Dec 1Now
- Garden peasOct 1 – Dec 1Now
- Onion plants plantsOct 1 – Dec 31Now
- SpinachOct 1 – Dec 1Now
- Upland cressOct 1 – Dec 1Now
- Chervil and chivesNov 1 – Dec 31Soon
- Onion setsNov 1 – Dec 31Soon
USDA lists horseradish as generally spring-planted here.
Spring planting
USDA dates for places whose average last freeze is about March 20 (Lake Oswego: March 18).
- Corn saladJan 1 – Mar 15
- RutabagaJan 15 – Mar 1
- SpinachJan 15 – Mar 15
- RadishesJan 20 – May 1
- Asparagus plantsFeb 1 – Mar 10
- Cabbage plantsFeb 1 – Mar 1
- Garden peasFeb 1 – Mar 15
- GarlicFeb 1 – Mar 1
- Leaf lettuceFeb 1 – Apr 1
- LeeksFeb 1 – Mar 1
- Onion setsFeb 1 – Mar 20
- ShallotsFeb 1 – Mar 10
- Cauliflower plantsFeb 10 – Mar 10
- Chervil and chivesFeb 10 – Mar 10
- DandelionFeb 10 – Mar 10
- Onion plants plantsFeb 10 – Mar 10
- Onion seedFeb 10 – Mar 10
- PotatoesFeb 10 – Mar 15
- SorrelFeb 10 – Mar 20
- TurnipsFeb 10 – Mar 10
- BeetsFeb 15 – May 15
- Broccoli plantsFeb 15 – Mar 15
- Brussels sprouts plantsFeb 15 – Mar 15
- CarrotsFeb 15 – Mar 20
- Collards plantsFeb 15 – May 1
- Head lettuce plantsFeb 15 – Mar 10
- ParsleyFeb 15 – Mar 15
- ParsnipsFeb 15 – Mar 15
- SalsifyFeb 15 – Mar 1
- KaleFeb 20 – Mar 10
- KohlrabiFeb 20 – Mar 10
- Mustard greensFeb 20 – Apr 1
- Swiss chardFeb 20 – May 15
- Upland cressFeb 20 – Mar 15
- Celery and celeriac plantsMar 1 – Apr 1
- EndiveMar 1 – Apr 1
- Florence fennelMar 1 – Apr 1
- Snap beansMar 15 – May 25
- Sweet cornMar 15 – May 1
- Black-eyed peasApr 1 – July 1
- Cantaloupe (muskmelon)Apr 1 – May 1
- CucumbersApr 1 – May 1
- Eggplant plantsApr 1 – May 1
- Lima beansApr 1 – June 15
- New Zealand spinachApr 1 – May 15
- OkraApr 1 – June 15
- Summer squashApr 1 – May 15
- TomatoesApr 1 – May 20
- WatermelonApr 1 – May 1
- Peppers plantsApr 10 – June 1
- SoybeansApr 10 – June 30
- Sweet potatoesApr 10 – June 1
- Witloof chicoryJune 1 – July 1
USDA lists chinese cabbage as generally fall-planted here.
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5 (earliest safe spring and latest safe fall dates), applied to this place's NOAA frost dates. “Plants” means setting out transplants, not sowing seed. How we match the table.