Kittitas 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.
Among the crops suited to this profile: cabbage, pawpaw, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Kittitas County lies within 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
Kittitas County holds more than one microclimate.
Soils and elevations shift across Kittitas 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 Kittitas County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Kittitas County — the short answer
Kittitas County, Washington: USDA zone 7a, about 194 days between hard freezes, across 1.5M acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 24
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~194
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.5M 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 Kittitas County's average, not your lot's — a low corner or a tree line moves it. Against Kittitas County's 194-day season, see what your own ground reads.
Heat in Kittitas County
Across a year, Kittitas County accumulates about 1,740 growing degree days above 50°F, about 27 more than the middle Washington county — ahead of 22 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 Kittitas County
Across Kittitas County, the ground is predominantly Mollisols, where Nard, Jumpe, and Vantage are the most extensive named soil series. The soil is generally well drained with a very cobbly loam surface. Topsoil pH runs about 6.1–7.0, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
2%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Kittitas County
The USDA soil survey maps 81% of Kittitas County as well drained — but another 13% drains differently: 7% moderately well drained, 3% somewhat poorly drained.
Nard is the most extensive named soil at 4% of mapped acres, then Jumpe (4%) and Vantage (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 Kittitas County
Each reading below is measured for Kittitas 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 Kittitas County are well drained, in hydrologic group C — 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 Kittitas County runs about pH 6.1–7.0, 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
MeasuredKittitas County runs about 194 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredKittitas 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 Kittitas County is in
Kittitas County spans 4 EPA Level III ecoregions — Columbia Plateau (44%), North Cascades (31%), Eastern Cascades Slopes and Foothills (20%) and Cascades (6%). 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 Kittitas County
We scored all 1,086 plants against Kittitas County's own USDA zone 7a and its own 194-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 Kittitas County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 24 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Kittitas County
- monarch butterfly4 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Kittitas County
USGS estimates 4,287 lb of Triclopyr on Kittitas County farmland in 2019, its largest by weight, ahead of Glyphosate (4,027 lb) and Metribuzin (2,392 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 Kittitas County — and how to grow with it.
We checked the federal record across Kittitas County — 367 documented sites across 8 of the 9 source types we track.
The most significant on record: 1 Superfund site (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Kittitas County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Kittitas County
Closest first, across Kittitas County. Listing isn't leaking, and distance isn't exposure.
- THORP SCHOOL DISTRICT 400Underground Storage Tanks · 3.7 mi
- 18N/17E-12M01 PAS23Nitrate · 4.2 mi
- KITTITAS SERVICE CENTERUnderground Storage Tanks · 4.8 mi
- THORP FUELUnderground Storage Tanks · 4.9 mi
- BINGO FUEL STOPUnderground Storage Tanks · 4.9 mi
- MINERAL SPRINGS RESORTUnderground Storage Tanks · 5.0 mi
- 19N/16E-25C02 PAS05Nitrate · 5.1 mi
- BRISTOL PRINT 457 MICROWAVEUnderground Storage Tanks · 6.1 mi
- Negro Creek IronMining · 6.5 mi
- Red Bridge Rd PropertyUnderground Storage Tanks · 7.3 mi
- 18N/18E-32D01Nitrate · 8.1 mi
- US DOE BPA SCHULTZ MAINTENANCE HQBrownfields · 8.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kittitas 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 Kittitas County.
Total Sites
367
across Kittitas County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Severity Distribution
across Kittitas County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Kittitas County, Mining runs higher than the national average — 117 sites across Kittitas County. That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Kittitas 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 Kittitas County average
Your land is one point inside Kittitas County
Everything above resolves to Kittitas County as a whole — one PHZM band and one county frost record, read across 1.5M 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 Kittitas County Average
Kittitas County Average
- ●USDA Zones 7a, averaged across Kittitas County
- ●One soil character for all of Kittitas County
- ●Frost dates read at Kittitas County's scale: Apr 13 to Oct 24
YOUR Parcel
- ✓Your exact zone, not Kittitas County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Kittitas County
Pull a site-specific report for your exact address in Kittitas County, Washington — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kittitas County averages can't show:
We read public map data around Kittitas County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kittitas County average
How we know this about Kittitas 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 Kittitas County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Kittitas County
When does frost risk typically end in Kittitas County?
The last hard freeze (28°F) in Kittitas County typically lands around Apr 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 May 4.
How long is the growing season in Kittitas County?
Measured between 28°F hard freezes, Kittitas County sees about 194 frost-free days — roughly Apr 13 through Oct 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 10, about 159 days.
Is the soil safe to grow vegetables in Kittitas County?
The federal record around Kittitas County is a meaningful one — 367 documented sites, mostly Underground Storage Tanks entries (191), the nearest Underground Storage Tanks record about 3.7 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.
Everything above is measured at Kittitas County's scale — its 7a band and its 194-day season. Your yard writes its own version of Kittitas 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 Kittitas County’s own scale
9 of the readings below were taken at Kittitas County's own scale — its own ~194-day span between 28°F freezes, the 3 most extensive soil series mapped here and 367 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Kittitas County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Kittitas County's own 28°F hard-freeze dates and its ~194-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Kittitas CountyUSDA NRCS SSURGO
- 367 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 3.7 miles outFederal environmental registers
- Kittitas County's boundary and the 1,470,265 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~194-day seasonGrowable Ground crop-matching engine
- The 4 ecoregions Kittitas County spans, Columbia Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Kittitas County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Kittitas 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 Kittitas County — the ~194 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 Kittitas County's 1,470,265 acreswhy one lot differs from the next →
- Which of those 367 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 Kittitas Countyread your own land →