Onalaska, Washington, sits in USDA hardiness zone 8b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, fig, california poppy, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Onalaska, 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 Onalaska 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 Onalaska — soil, climate, flood, and parcel records. How we handle your address.
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Onalaska — the short answer
Onalaska, Washington: USDA zone 8b, about 243 days between hard freezes, across 1K acres of town.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 22
- Lewis County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 20
- Lewis County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~243
- Lewis County normal — NOAA 1991–2020, nearest to this town
- Town area
- 1K 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 Lewis County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Onalaska's average, not your lot's — a low corner or a tree line moves it. Against Onalaska's 243-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Onalaska
Each reading below is measured for Onalaska itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsOnalaska runs about 243 days between hard freezes (read from Lewis County, the closest normal to Onalaska) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredOnalaska sits in USDA hardiness zone 8b.
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 Onalaska is in
Onalaska sits in the Puget Lowland — EPA Level III, inside the wider Marine West Coast Forest. That is read at Onalaska's own centroid, and it is not what its county reads: Lewis County is mostly Cascades. The wider page above you is answering a different question about different ground.
What Grows in Onalaska
Every plant below cleared Onalaska's own zone 8b and its 243-day season. Each card opens that plant's Washington profile. How we score.
Is it too late to plant in Onalaska?
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 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 20 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near Onalaska
Closest first, within ~10 miles of Onalaska. Listing isn't leaking, and distance isn't exposure.
- DORSEY BUS SERVICE INCUnderground Storage Tanks · 2400 ft
- BRENDA'S COUNTRY MARKETUnderground Storage Tanks · 0.7 mi
- CJC WEST LLCBrownfields · 1.2 mi
- CJC WEST LLCSuperfund · 1.2 mi
- 13N/01E-19K02Nitrate · 1.3 mi
- LEWIS COUNTY FIRE DISTRICT 1Brownfields · 1.4 mi
- DRAPER VALLEY FARMS 765CAFO · 1.6 mi
- 13N/01W-25B01Nitrate · 2.0 mi
- STANLEY STOREUnderground Storage Tanks · 3.2 mi
- SHOP REPAIRS LOGGINGUnderground Storage Tanks · 3.3 mi
- DASHMESH PETROLEUM - QUICK STOPUnderground Storage Tanks · 3.3 mi
- 12N/01E-09Q01Nitrate · 3.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Onalaska'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 Onalaska.
Total Sites
348
within ~10 miles of Onalaska
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Onalaska
Severity Distribution
within ~10 miles of Onalaska
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Onalaska, two things run higher than the national average within ~10 miles of Onalaska — Nitrate (282 sites) and CAFO (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Onalaska
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 Onalaska average
Your land is one point inside Onalaska
Everything above resolves to Onalaska as a whole — one PHZM band, read across 1K acres, with hard-freeze dates borrowed from Lewis County’s record because no 30-year normal resolves at this town’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 town 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 Onalaska Average
Onalaska Average
- ●USDA Zones 8b, averaged across Onalaska
- ●One soil character for all of Onalaska
- ●Frost dates read at Onalaska's scale: Mar 22 to Nov 20
YOUR Parcel
- ✓Your exact zone, not Onalaska's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Onalaska
Pull a site-specific report for your exact address in Onalaska, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Onalaska averages can't show:
We read public map data around Onalaska — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Onalaska average
How we know this about Onalaska
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Lewis 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 town grain anywhere on this page — there is no town-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 Onalaska
When does frost risk typically end in Onalaska?
The last hard freeze (28°F) in Onalaska typically lands around Mar 22, 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 Apr 12.
When is the first frost in Onalaska?
The first hard freeze (28°F) in Onalaska typically arrives around Nov 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 6, so the watching starts about Oct 21 — about 243 days after the spring freeze cleared.
How long is the growing season in Onalaska?
Measured between 28°F hard freezes, Onalaska sees about 243 frost-free days — roughly Mar 22 through Nov 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 12 to Nov 6, about 208 days.
Is the soil safe to grow vegetables in Onalaska?
The federal record around Onalaska is a meaningful one — 348 documented sites, mostly Nitrate entries (282), the nearest Underground Storage Tanks record about 0.5 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 Onalaska?
From about Oct 21 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Onalaska's scale — its 8b band and its 243-day season. Your yard writes its own version of Onalaska'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 Onalaska’s own scale
5 of the readings below were taken at Onalaska's own scale — the 1,027 acres it covers and 348 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Onalaska's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 348 documented contamination sites on the federal record near Onalaska, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- Onalaska's boundary and the 1,027 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~243-day seasonGrowable Ground crop-matching engine
- Onalaska sits in the Puget Lowland — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Onalaska has no normal of its own, so its county's is the closest measured readfrom Lewis County
- Soil character — no town-scale survey exists, so Onalaska's 1,027 acres read through its county's SSURGO summaryfrom Lewis County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lewis County
- The growing challenges every Washington grower plans around — written at state scale, so they stay on the state guidefrom Washington
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Lewis County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Onalaska's 1,027 acreswhy one lot differs from the next →
- Which side of Onalaska you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,027 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 Onalaska-wide figureread your own land →
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