St. Helens, Oregon, sits in USDA hardiness zone 8a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Reliable performers under these conditions include cabbage, fig, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in St. Helens, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single St. Helens lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around St. Helens — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
St. Helens — the short answer
St. Helens, Oregon: USDA zone 8a, about 262 days between hard freezes, across 3K acres of city.
- USDA zone
- 8a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 9
- Columbia County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 26
- Columbia County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~262
- Columbia County normal — NOAA 1991–2020, nearest to this town
- City area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Columbia County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8a is St. Helens's average, not your lot's — a low corner or a tree line moves it. Against St. Helens's 262-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in St. Helens
Each reading below is measured for St. Helens itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSt. Helens runs about 262 days between hard freezes (read from Columbia County, the closest normal to St. Helens) — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSt. Helens sits in USDA hardiness zone 8a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country St. Helens is in
St. Helens sits in the Willamette Valley — EPA Level III, inside the wider Marine West Coast Forest. That is read at St. Helens's own centroid, and it is not what its county reads: Columbia County is mostly Coast Range. The wider page above you is answering a different question about different ground.
What Grows in St. Helens
Every plant below cleared St. Helens's own zone 8a and its 262-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in St. Helens?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 26 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around St. Helens
Survey cells within 31 miles of St. Helens checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 561 miles off. What to watch for.
What's on the federal record near St. Helens
Closest first, within ~10 miles of St. Helens. Listing isn't leaking, and distance isn't exposure.
- ST HELENS DISTRICTUnderground Storage Tanks · 1100 ft
- EATON'S TIRE & USED CAR CENTERUnderground Storage Tanks · 1200 ft
- LEWELLEN MOTOR COMPANYUnderground Storage Tanks · 1300 ft
- JOHNSTUNS DRYCLEANERSBrownfields · 1400 ft
- AL'S AUTOMATIC TRANSMISSIONUnderground Storage Tanks · 1500 ft
- UNOCAL 5218Underground Storage Tanks · 1500 ft
- JENSEN, DONUnderground Storage Tanks · 1600 ft
- ST HELENS CHEVRONUnderground Storage Tanks · 1600 ft
- ROFINOT MOBIL DIST INCUnderground Storage Tanks · 1600 ft
- DON'S RENTAL INCUnderground Storage Tanks · 1600 ft
- BERNHARDT, JOHNUnderground Storage Tanks · 1600 ft
- ST HELENS CITY OF PARKS DEPTBrownfields · 1700 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Helens's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near St. Helens.
Total Sites
275
within ~10 miles of St. Helens
Risk Level
Elevated
Highest-severity
7 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of St. Helens
Severity Distribution
within ~10 miles of St. Helens
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Helens, two things run higher than the national average within ~10 miles of St. Helens — Superfund (7 sites) and PFAS (4 sites). That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in St. Helens
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the St. Helens average
Your land is one point inside St. Helens
Everything above resolves to St. Helens as a whole — one PHZM band, read across 3K acres, with hard-freeze dates borrowed from Columbia County’s record because no 30-year normal resolves at this city’s own centroid. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at city scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.
Your Lot vs the St. Helens Average
St. Helens Average
- ●USDA Zones 8a, averaged across St. Helens
- ●One soil character for all of St. Helens
- ●Frost dates read at St. Helens's scale: Mar 9 to Nov 26
YOUR Parcel
- ✓Your exact zone, not St. Helens's 8a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in St. Helens
Pull a site-specific report for your exact address in St. Helens, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Helens averages can't show:
We read public map data around St. Helens — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Helens average
How we know this about St. Helens
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Columbia County’s record, because none resolves here; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about St. Helens
When does frost risk typically end in St. Helens?
The last hard freeze (28°F) in St. Helens typically lands around Mar 9, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Mar 30.
When is the first frost in St. Helens?
The first hard freeze (28°F) in St. Helens typically arrives around Nov 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 12, so the watching starts about Oct 27 — about 262 days after the spring freeze cleared.
How long is the growing season in St. Helens?
Measured between 28°F hard freezes, St. Helens sees about 262 frost-free days — roughly Mar 9 through Nov 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 30 to Nov 12, about 227 days.
Is the soil safe to grow vegetables in St. Helens?
The federal record around St. Helens is a meaningful one — 275 documented sites, mostly Underground Storage Tanks entries (166), the nearest Underground Storage Tanks record about 0.2 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in St. Helens?
From about Oct 27 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 26 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at St. Helens's scale — its 8a band and its 262-day season. Your yard writes its own version of St. Helens's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at St. Helens’s own scale
6 of the readings below were taken at St. Helens's own scale — the 3,108 acres it covers and 275 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- St. Helens's own USDA hardiness band, zones 8aUSDA PHZM 2023
- 275 documented contamination sites on the federal record near St. Helens, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- St. Helens's boundary and the 3,108 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8a and a ~262-day seasonGrowable Ground crop-matching engine
- St. Helens sits in the Willamette Valley — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- Lanternfly survey cells around St. Helens checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — St. Helens has no normal of its own, so its county's is the closest measured readfrom Columbia County
- Soil character — no town-scale survey exists, so St. Helens's 3,108 acres read through its county's SSURGO summaryfrom Columbia County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Columbia County
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Columbia County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among St. Helens's 3,108 acreswhy one lot differs from the next →
- Which side of St. Helens you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,108 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any St. Helens-wide figureread your own land →
More in Oregon
Growing region
Nearby growing guides