Last frost date in St. Helens, Oregon
April 18
Average last frost in spring. In an early year (1 in 10) it's over by March 20; in a late year (1 in 10) it comes after May 26.
November 7
Average first frost in fall. 1 year in 10 it comes by October 21.
Source: NOAA U.S. Climate Normals 1991–2020, station Saint Helens Rfd (USC00357466), 2.7 miles from St. Helens, elevation 269 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Mar 20 | Apr 18 | May 26 |
| First frost in fall | Oct 21 | Nov 7 | Nov 26 |
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: 201
Planting calendar for St. Helens
Fall planting
USDA dates for places whose average first freeze is about November 10 (St. Helens: November 7).
- CucumbersJune 1 – Aug 15 (past for this year)
- Eggplant plantsJune 1 – July 15 (past for this year)
- New Zealand spinachJune 1 – Aug 15 (past for this year)
- OkraJune 1 – Aug 20 (past for this year)
- Peppers plantsJune 1 – Aug 1 (past for this year)
- SoybeansJune 1 – July 25 (past for this year)
- Summer squashJune 1 – Aug 10 (past for this year)
- Sweet cornJune 1 – Aug 15 (past for this year)
- Sweet potatoesJune 1 – July 1 (past for this year)
- Swiss chardJune 1 – Sept 15 (past for this year)
- TomatoesJune 1 – July 15 (past for this year)
- Black-eyed peasJune 15 – Aug 15 (past for this year)
- SalsifyJune 15 – July 20 (past for this year)
- Winter squashJune 20 – July 20 (past for this year)
- Celery and celeriac plantsJuly 1 – Aug 15 (past for this year)
- Lima beansJuly 1 – Aug 15 (past for this year)
- Snap beansJuly 1 – Sept 1 (past for this year)
- Witloof chicoryJuly 10 – Aug 20 (past for this year)
- Cantaloupe (muskmelon)July 15 – 30 (past for this year)
- Florence fennelJuly 15 – Aug 15 (past for this year)
- RutabagaJuly 15 – Aug 15 (past for this year)
- WatermelonJuly 15 – 30 (past for this year)
- PotatoesJuly 25 – Aug 20 (past for this year)
- BeetsAug 1 – Oct 1 (past for this year)
- Broccoli plantsAug 1 – Sept 1 (past for this year)
- Brussels sprouts plantsAug 1 – Sept 1 (past for this year)
- CarrotsAug 1 – Sept 1 (past for this year)
- Cauliflower plantsAug 1 – Sept 1 (past for this year)
- EndiveAug 1 – Sept 1 (past for this year)
- GarlicAug 1 – Oct 1 (past for this year)
- KaleAug 1 – Sept 15 (past for this year)
- ShallotsAug 1 – Oct 1 (past for this year)
- Chinese cabbageAug 15 – Oct 1 (past for this year)
- Collards plantsAug 15 – Oct 1 (past for this year)
- Head lettuce plantsAug 15 – Oct 15 (past for this year)
- KohlrabiAug 15 – Sept 15 (past for this year)
- Mustard greensAug 15 – Nov 1Now
- SorrelAug 15 – Oct 1 (past for this year)
- Leaf lettuceAug 25 – Oct 1 (past for this year)
- Cabbage plantsSept 1 – 15 (past for this year)
- DandelionSept 1 – Oct 15 (past for this year)
- Garden peasSept 1 – Nov 1Now
- Onion plants plantsSept 1 – Oct 15 (past for this year)
- ParsleySept 1 – Nov 15Now
- RadishesSept 1 – Nov 15Now
- TurnipsSept 1 – Oct 15 (past for this year)
- SpinachSept 15 – Nov 1Now
- Corn saladOct 1 – Dec 1Now
- Onion setsOct 1 – Dec 1Now
- Upland cressOct 1 – Dec 1Now
- Asparagus plantsDec 1 – Jan 1Soon
USDA lists chervil and chives, horseradish, leeks, parsnips as generally spring-planted here.
Spring planting
USDA dates for places whose average last freeze is about April 20 (St. Helens: April 18).
- Corn saladFeb 15 – Apr 15
- SpinachMar 1 – Apr 15
- Cabbage plantsMar 10 – Apr 1
- Chervil and chivesMar 10 – Apr 10
- Collards plantsMar 10 – June 1
- DandelionMar 10 – Apr 10
- Garden peasMar 10 – Apr 10
- GarlicMar 10 – Apr 1
- Onion setsMar 10 – Apr 1
- RadishesMar 10 – May 10
- Rhubarb plantsMar 10 – Apr 10
- TurnipsMar 10 – Apr 1
- Asparagus plantsMar 15 – Apr 15
- Cauliflower plantsMar 15 – Apr 20
- LeeksMar 15 – Apr 15
- Onion plants plantsMar 15 – Apr 10
- Onion seedMar 15 – Apr 1
- PotatoesMar 15 – Apr 10
- ShallotsMar 15 – Apr 15
- SorrelMar 15 – May 1
- BeetsMar 20 – June 1
- Head lettuce plantsMar 20 – Apr 15
- Horseradish plantsMar 20 – Apr 20
- KaleMar 20 – Apr 10
- KohlrabiMar 20 – May 1
- Leaf lettuceMar 20 – May 15
- Mustard greensMar 20 – May 1
- ParsleyMar 20 – Apr 20
- ParsnipsMar 20 – Apr 20
- SalsifyMar 20 – May 1
- Upland cressMar 20 – May 1
- Broccoli plantsMar 25 – Apr 20
- Brussels sprouts plantsMar 25 – Apr 20
- EndiveMar 25 – Apr 15
- Florence fennelMar 25 – Apr 15
- CarrotsApr 1 – May 15
- Swiss chardApr 1 – June 15
- Celery and celeriac plantsApr 10 – May 1
- Snap beansApr 25 – June 30
- Sweet cornApr 25 – June 15
- Cantaloupe (muskmelon)May 1 – June 15
- CucumbersMay 1 – June 15
- Lima beansMay 1 – June 20
- New Zealand spinachMay 1 – June 15
- OkraMay 1 – June 1
- Summer squashMay 1 – June 15
- WatermelonMay 1 – June 15
- TomatoesMay 5 – June 10
- Black-eyed peasMay 10 – June 15
- Eggplant plantsMay 10 – June 1
- Peppers plantsMay 10 – June 1
- SoybeansMay 10 – June 20
- Sweet potatoesMay 10 – June 10
- Witloof chicoryJune 15 – 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.
Nearby in Oregon
- Hillsboro 23 mi · last frost Apr 16
- Portland 23 mi · last frost Feb 25
- Cornelius 26 mi · last frost Apr 16
- Beaverton 26 mi · last frost Apr 1
- Forest Grove 27 mi · last frost Apr 16