Yakima County, in Washington, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, pawpaw, 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.
Yakima 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
Yakima County holds more than one microclimate.
Soils and elevations shift across Yakima 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 Yakima County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Yakima County — the short answer
Yakima County, Washington: USDA zone 7a, about 209 days between hard freezes, across 2.7M acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~209
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 2.7M 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 7a is Yakima County's average, not your lot's — a low corner or a tree line moves it. Against Yakima County's 209-day season, see what your own ground reads.
Heat in Yakima County
Across a year, Yakima County accumulates about 2,279 growing degree days above 50°F, about 566 more than the middle Washington county — ahead of 34 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 Yakima County
Across Yakima County, the ground is predominantly Mollisols, where Warden, Ritzville, and Singh are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.3–7.2, neutral. Rainfall drains through hydrologic group B soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
0%
Hydric soils
4%
Soil still varies lot by lot — soil types explained.
How the ground varies across Yakima County
The USDA soil survey maps 85% of Yakima County as well drained — but another 10% drains differently: 5% somewhat poorly drained, 3% somewhat excessively drained.
Warden is the most extensive named soil at 7% of mapped acres, then Ritzville (5%) and Singh (3%).
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 Yakima County
Each reading below is measured for Yakima 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 Yakima 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 Yakima County runs about pH 6.3–7.2, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredYakima County runs about 209 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
MeasuredYakima County sits in USDA hardiness zone 7a.
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 Yakima County is in
Yakima County spans 3 EPA Level III ecoregions — Columbia Plateau (55%), Eastern Cascades Slopes and Foothills (34%) and Cascades (11%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Yakima County
We scored all 1,086 plants against Yakima County's own USDA zone 7a and its own 209-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 Yakima County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — 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 Yakima County
- monarch butterfly11 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Yakima County
USGS estimates 99,967 lb of Chlorpyrifos on Yakima County farmland in 2019, its largest by weight, ahead of Glyphosate (75,622 lb) and Triclopyr (67,234 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 Yakima County — and how to grow with it.
We checked the federal record across Yakima County — 1,781 documented sites across 8 of the 9 source types we track.
The most significant on record: 13 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Yakima 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 Yakima County
Closest first, across Yakima County. Listing isn't leaking, and distance isn't exposure.
- 11N/16E-25N01Nitrate · 3.9 mi
- 11N/16E-35J01Nitrate · 4.5 mi
- 12N/17E-16R01Nitrate · 4.9 mi
- YAKAMA BUSINESS AND TECH CENTERToxics Release Inventory · 5.2 mi
- WHITE SWAN FIRE RESPONSESuperfund · 5.4 mi
- 12N/17E-16D03Nitrate · 5.5 mi
- 12N/16E-13D01Nitrate · 5.6 mi
- US DOI FT SIMCOE JOB CORP CTRSuperfund · 5.6 mi
- 12N/16E-17J01Nitrate · 7.1 mi
- 11N/18E-32D01Nitrate · 7.3 mi
- 11N/18E-29N01Nitrate · 7.3 mi
- 11N/18E-31A01Nitrate · 7.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Yakima 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 Yakima County.
Severity Distribution
across Yakima County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Yakima County, two things run higher than the national average across Yakima County — CAFO (35 sites) and Nitrate (784 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Yakima 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 Yakima County average
Your land is one point inside Yakima County
Everything above resolves to Yakima County as a whole — one PHZM band and one county frost record, read across 2.7M 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 Yakima County Average
Yakima County Average
- ●USDA Zones 7a, averaged across Yakima County
- ●One soil character for all of Yakima County
- ●Frost dates read at Yakima County's scale: Mar 30 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Yakima County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Yakima County
Pull a site-specific report for your exact address in Yakima County, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Yakima County averages can't show:
We read public map data around Yakima County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Yakima County average
How we know this about Yakima 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 Yakima County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Yakima County
When does frost risk typically end in Yakima County?
The last hard freeze (28°F) in Yakima County typically lands around Mar 30, 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 20.
How long is the growing season in Yakima County?
Measured between 28°F hard freezes, Yakima County sees about 209 frost-free days — roughly Mar 30 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 11, about 174 days.
Is the soil safe to grow vegetables in Yakima County?
The federal record around Yakima County runs heavier than most — 1,781 documented sites, mostly Nitrate entries (784), the nearest Nitrate record about 3.9 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 Yakima County's scale — its 7a band and its 209-day season. Your yard writes its own version of Yakima 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 Yakima County’s own scale
9 of the readings below were taken at Yakima County's own scale — its own ~209-day span between 28°F freezes, the 3 most extensive soil series mapped here and 1,781 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Yakima County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Yakima County's own 28°F hard-freeze dates and its ~209-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Yakima CountyUSDA NRCS SSURGO
- 1,781 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 3.9 miles outFederal environmental registers
- Yakima County's boundary and the 2,748,485 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~209-day seasonGrowable Ground crop-matching engine
- The 3 ecoregions Yakima County spans, Columbia Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Yakima County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Yakima 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 Yakima County — the ~209 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 Yakima County's 2,748,485 acreswhy one lot differs from the next →
- Which of those 1,781 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 Yakima Countyread your own land →