Benton County, in Washington, sits in USDA hardiness zone 7b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include cabbage, prickly pear, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Benton County lies within the Yakima Valley and the Columbia Basin — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Benton County holds more than one microclimate.
Soils and elevations shift across Benton 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 Benton County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Benton County — the short answer
Benton County, Washington: USDA zone 7b, about 222 days between hard freezes, across 1.1M acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~222
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.1M 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 7b is Benton County's average, not your lot's — a low corner or a tree line moves it. Against Benton County's 222-day season, see what your own ground reads.
Heat in Benton County
Across a year, Benton County accumulates about 2,461 growing degree days above 50°F, about 748 more than the middle Washington county — ahead of 36 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 Benton County
Across Benton County, the ground is predominantly Aridisols, where Ritzville, Warden, and Shano are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 7.2–7.6, slightly alkaline. Rainfall drains through hydrologic group B soils.
Soil order
Aridisols
Drainage
Well drained
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Benton County
The USDA soil survey maps 71% of Benton County as well drained — but another 26% drains differently: 20% excessively drained, 6% somewhat excessively drained.
Ritzville is the most extensive named soil at 20% of mapped acres, then Warden (16%) and Shano (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 Benton County
Each reading below is measured for Benton 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 Benton 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 Benton County runs about pH 7.2–7.6, on the alkaline side.
Many vegetables cope, but acid-lovers like blueberries struggle, and iron and manganese lock up above about pH 7.5 — leaves yellow between the veins even in rich soil.
Elemental sulfur and generous organic matter lower pH slowly for the beds that need it; test first so you add only what the soil actually calls for.
USDA NRCS SSURGO
Season length
MeasuredBenton County runs about 222 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
MeasuredBenton County sits in USDA hardiness zone 7b.
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 Benton County is in
Benton County sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. One consistent ecological setting across the whole county.
What Grows in Benton County
We scored all 1,086 plants against Benton County's own USDA zone 7b and its own 222-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 Benton County?
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 Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 9 — 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.
Documented around Benton County
- monarch butterfly96 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Benton County
USGS estimates 136,780 lb of Glyphosate on Benton County farmland in 2019, its largest by weight, ahead of 2,4-d (85,922 lb) and Metolachlor-s (47,056 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 Benton County — and how to grow with it.
We checked the federal record across Benton County — 922 documented sites across 6 of the 9 source types we track.
The most significant on record: 10 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Benton County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Benton County
Closest first, across Benton County. Listing isn't leaking, and distance isn't exposure.
- 09N/26E-27K01Nitrate · 1.2 mi
- UPRR BENTON CITYUnderground Storage Tanks · 2.4 mi
- DESERT FOOD MARTUnderground Storage Tanks · 2.6 mi
- BROOK + WHITTLE BENTON CITYBrownfields · 2.7 mi
- PIK A POP IIUnderground Storage Tanks · 2.7 mi
- BENTON CITY CENTRAL OFFICE 4020-B01Underground Storage Tanks · 2.8 mi
- BENTON CITY MAINTENANCE YARDUnderground Storage Tanks · 2.9 mi
- KIONA-BENTON CITY SCHOOL DISTRICT BUS BARNUnderground Storage Tanks · 2.9 mi
- JUST A MINUTE MARTUnderground Storage Tanks · 2.9 mi
- BURRUSS DISTRIBUTING INCUnderground Storage Tanks · 3.0 mi
- KIONA BENTON CITY SCHOOL DISTUnderground Storage Tanks · 3.2 mi
- 09N/27E-17P02Nitrate · 3.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Benton 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 Benton County.
Sources Checked
across Benton County
Severity Distribution
across Benton County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Benton County, Nitrate runs higher than the national average — 374 sites across Benton County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Benton 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 Benton County average
Your land is one point inside Benton County
Everything above resolves to Benton County as a whole — one PHZM band and one county frost record, read across 1.1M 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 Benton County Average
Benton County Average
- ●USDA Zones 7b, averaged across Benton County
- ●One soil character for all of Benton County
- ●Frost dates read at Benton County's scale: Apr 1 to Nov 9
YOUR Parcel
- ✓Your exact zone, not Benton County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Benton County
Pull a site-specific report for your exact address in Benton County, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Benton County averages can't show:
We read public map data around Benton County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Benton County average
How we know this about Benton 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 Benton County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Benton County
When does frost risk typically end in Benton County?
The last hard freeze (28°F) in Benton County typically lands around Apr 1, 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 22.
How long is the growing season in Benton County?
Measured between 28°F hard freezes, Benton County sees about 222 frost-free days — roughly Apr 1 through Nov 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Oct 26, about 187 days.
Is the soil safe to grow vegetables in Benton County?
The federal record around Benton County runs heavier than most — 922 documented sites, mostly Underground Storage Tanks entries (378), the nearest Nitrate record about 1.2 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Benton County's scale — its 7b band and its 222-day season. Your yard writes its own version of Benton 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 Benton County’s own scale
9 of the readings below were taken at Benton County's own scale — its own ~222-day span between 28°F freezes, the 3 most extensive soil series mapped here and 922 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Benton County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Benton County's own 28°F hard-freeze dates and its ~222-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Benton CountyUSDA NRCS SSURGO
- 922 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 1.2 miles outFederal environmental registers
- Benton County's boundary and the 1,088,081 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~222-day seasonGrowable Ground crop-matching engine
- Benton County sitting wholly inside the Columbia PlateauUS EPA Level III Ecoregions
- Open occurrence records documented in Benton County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Benton 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 Benton County — the ~222 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 Benton County's 1,088,081 acreswhy one lot differs from the next →
- Which of those 922 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 Benton Countyread your own land →