Wahkiakum County, in Washington, sits in USDA hardiness zone 8b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include cabbage, fig, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Wahkiakum County lies within the Lower Columbia / Southwest Washington (Vancouver-Longview) and the Pacific Northwest — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Wahkiakum County holds more than one microclimate.
Soils and elevations shift across Wahkiakum County, so your frost dates and drainage aren't the county average. 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 Wahkiakum County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Wahkiakum County — the short answer
Wahkiakum County, Washington: USDA zone 8b, about 249 days between hard freezes, across 168K acres.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 13
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 17
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~249
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 168K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 8b is Wahkiakum County's average, not your lot's — a low corner or a tree line moves it. Against Wahkiakum County's 249-day season, see what your own ground reads.
Heat in Wahkiakum County
Across a year, Wahkiakum County accumulates about 1,486 growing degree days above 50°F, about 227 fewer than the middle Washington county — ahead of 15 of Washington’s 39 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Wahkiakum County
Across Wahkiakum County, the ground is predominantly Andisols, where Hoquiam, Knappton, and Willapa are the most extensive named soil series. The soil is generally well drained with a medial silt loam surface. Topsoil pH runs about 4.6–5.3, very strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Andisols
Drainage
Well drained
Prime farmland
14%
Hydric soils
7%
Soil still varies lot by lot — soil types explained.
How the ground varies across Wahkiakum County
The USDA soil survey maps 73% of Wahkiakum County as well drained — but another 25% drains differently: 11% moderately well drained, 5% poorly drained.
Hoquiam is the most extensive named soil at 7% of mapped acres, then Knappton (6%) and Willapa (6%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Wahkiakum County
Each reading below is measured for Wahkiakum County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Wahkiakum County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Wahkiakum County runs about pH 4.6–5.3, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredWahkiakum County runs about 249 days between hard freezes — 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
MeasuredWahkiakum County 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 Wahkiakum County is in
Wahkiakum County sits in the Coast Range — EPA Level III, inside the wider Marine West Coast Forest. One consistent ecological setting across the whole county.
What Grows in Wahkiakum County
We scored all 1,086 plants against Wahkiakum County's own USDA zone 8b and its own 249-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Washington profile.
Is it too late to plant in Wahkiakum County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 17 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Wahkiakum County
- monarch butterfly5 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Wahkiakum County
USGS estimates 277 lb of 2,4-d on Wahkiakum County farmland in 2019, its largest by weight, ahead of Simazine (260 lb) and Glyphosate (176 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Wahkiakum County — and how to grow with it.
We checked the federal record across Wahkiakum County — 23 documented sites across 3 of the 9 source types we track.
The most significant on record: 3 brownfield sites. Former commercial or industrial land where legacy contamination may persist.
The federal record across Wahkiakum County is light. Growing food here starts from a strong position — a quick pass over the map tells you whether any recorded site sits near your land, and if one does, that's information to plant with, not a reason to stop.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Wahkiakum County
Closest first, across Wahkiakum County. Listing isn't leaking, and distance isn't exposure.
- WAHKIAKUM COUNTY FIRE PROTECTION DISTRICT 2 SKAMOKAWABrownfields · 2.1 mi
- GEORGETTE MADDEN WHOLESALEUnderground Storage Tanks · 2.3 mi
- BURNS ROCK&REDI MIXUnderground Storage Tanks · 4.6 mi
- WAHKIAKUM COUNTY PORT DISTRICTUnderground Storage Tanks · 4.6 mi
- ROAD DEPT SHOP 1Underground Storage Tanks · 5.7 mi
- TOWN OF CATHLAMET WTPBrownfields · 6.1 mi
- 08N/06W-02G01Nitrate · 6.2 mi
- WA DWF ELOCHOMAN HATCHERYUnderground Storage Tanks · 6.4 mi
- BUS GARAGEUnderground Storage Tanks · 6.4 mi
- WAHKIAKUM PUD 1Underground Storage Tanks · 6.5 mi
- 09N/05W-32C02Nitrate · 6.5 mi
- CATHLAMETUnderground Storage Tanks · 6.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Wahkiakum County'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 Wahkiakum County.
Severity Distribution
across Wahkiakum County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Wahkiakum County
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 Wahkiakum County average
Your land is one point inside Wahkiakum County
Everything above resolves to Wahkiakum County as a whole — one PHZM band and one county frost record, read across 168K acres. 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 county 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 county average.
Your Lot vs the Wahkiakum County Average
Wahkiakum County Average
- ●USDA Zones 8b, averaged across Wahkiakum County
- ●One soil character for all of Wahkiakum County
- ●Frost dates read at Wahkiakum County's scale: Mar 13 to Nov 17
YOUR Parcel
- ✓Your exact zone, not Wahkiakum County's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Wahkiakum County
Pull a site-specific report for your exact address in Wahkiakum County, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Wahkiakum County averages can't show:
We read public map data around Wahkiakum County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wahkiakum County average
How we know this about Wahkiakum County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Wahkiakum County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Wahkiakum County
When does frost risk typically end in Wahkiakum County?
The last hard freeze (28°F) in Wahkiakum County typically lands around Mar 13, 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 3.
How long is the growing season in Wahkiakum County?
Measured between 28°F hard freezes, Wahkiakum County sees about 249 frost-free days — roughly Mar 13 through Nov 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 3 to Nov 3, about 214 days.
Is the soil safe to grow vegetables in Wahkiakum County?
The federal record around Wahkiakum County is light — 23 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (16), the nearest Brownfields record about 2.1 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
Everything above is measured at Wahkiakum County's scale — its 8b band and its 249-day season. Your yard writes its own version of Wahkiakum County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Washington's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Wahkiakum County’s own scale
9 of the readings below were taken at Wahkiakum County's own scale — its own ~249-day span between 28°F freezes, the 3 most extensive soil series mapped here and 23 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Wahkiakum County's own USDA hardiness band, zones 8bUSDA PHZM 2023
- Wahkiakum County's own 28°F hard-freeze dates and its ~249-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Wahkiakum CountyUSDA NRCS SSURGO
- 23 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 2.1 miles outFederal environmental registers
- Wahkiakum County's boundary and the 168,274 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~249-day seasonGrowable Ground crop-matching engine
- Wahkiakum County sitting wholly inside the Coast RangeUS EPA Level III Ecoregions
- Open occurrence records documented in Wahkiakum County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Wahkiakum County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Washington grower plans around — written at state scale, so they stay on the state guidefrom Washington
What this page can’t tell you
- How the season shifts across Wahkiakum County — the ~249 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Wahkiakum County's 168,274 acreswhy one lot differs from the next →
- Which of those 23 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Wahkiakum Countyread your own land →