Klamath County, in Oregon, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include pumpkin, blackberry, california poppy, and zucchini; what your own ground favors still comes down to its soil, sun, and drainage.
Klamath County lies within the Klamath Basin — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Klamath County holds more than one microclimate.
Soils and elevations shift across Klamath 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 Klamath County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Klamath County — the short answer
Klamath County, Oregon: USDA zone 6a, about 86 days between hard freezes, across 3.8M acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jun 9
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Sep 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~86
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 3.8M 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 6a is Klamath County's average, not your lot's — a low corner or a tree line moves it. Against Klamath County's 86-day season, see what your own ground reads.
One county, several growing seasons
Klamath County's hard-freeze record runs about 86 days between freezes — but that is the county-wide average, and several towns inside it carry a markedly different season in their own 30-year record: Falcon Heights at about 140 days and Keno at 132 (against the county's ~86).
Those are measured records, not estimates. If you garden in one of these pockets, plant against your own town's season rather than the county's ~86-day average.
NOAA Regional Climate Centers ACIS (1991–2020), 30-year daily minimum record. Only held-out towns carrying their own record are named — a town with no record of its own is absent rather than estimated, and a county with nothing qualifying shows no spread at all.
Heat in Klamath County
Across a year, Klamath County accumulates about 1,104 growing degree days above 50°F, about 748 fewer than the middle Oregon county — no other Oregon county banks fewer. 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 Klamath County
Across Klamath County, the ground is predominantly Mollisols, where Lapine, Lorella, and Steiger are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.3–7.0, neutral. Rainfall drains through hydrologic group A soils.
Soil order
Mollisols
Drainage
Well drained
Hydric soils
15%
Soil still varies lot by lot — soil types explained.
How the ground varies across Klamath County
The USDA soil survey maps 41% of Klamath County as well drained — but another 50% drains differently: 20% excessively drained, 12% somewhat excessively drained.
Lapine is the most extensive named soil at 17% of mapped acres, then Lorella (11%) and Steiger (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 Klamath County
Each reading below is measured for Klamath 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 Klamath County are well drained, in hydrologic group A — 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 Klamath County runs about pH 6.3–7.0, 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
Wet ground
MeasuredAbout 15% of Klamath County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredKlamath County runs about 86 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
The kind of country Klamath County is in
Klamath County spans 2 EPA Level III ecoregions — Eastern Cascades Slopes and Foothills (86%) and Cascades (14%). 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 Klamath County
We scored all 1,086 plants against Klamath County's own USDA zone 6a and its own 86-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 Oregon profile.
Is it too late to plant in Klamath County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around May 12; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jun 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 3 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
Documented around Klamath County
- monarch butterfly91 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Klamath County
USGS estimates 27,552 lb of Glyphosate on Klamath County farmland in 2019, its largest by weight, ahead of Carbaryl (15,477 lb) and Metolachlor-s (7,654 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 Klamath County — and how to grow with it.
We checked the federal record across Klamath County — 489 documented sites across 8 of the 9 source types we track.
The most significant on record: 7 Superfund sites. 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 Klamath 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 Klamath County
Closest first, across Klamath County. Listing isn't leaking, and distance isn't exposure.
- THUNDERBEAST PARKUnderground Storage Tanks · 8.8 mi
- CHILOQUIN RS - WINEMA NAT'L FORESTUnderground Storage Tanks · 10.4 mi
- USDOI FWS KLAMATH NATIONAL WILDLIFE REFBrownfields · 10.7 mi
- AT&TUnderground Storage Tanks · 12.2 mi
- UNION PACIFIC CHILOQUIN YARDUnderground Storage Tanks · 13.2 mi
- TELEPHONE UTILITIES OF EASTERN OREGONUnderground Storage Tanks · 13.2 mi
- CHILOQUIN TEXACO (FORMER)Underground Storage Tanks · 13.2 mi
- FORMER MARKWARDT BROTHERS GARAGEBrownfields · 13.3 mi
- MAY-SLADE OIL COUnderground Storage Tanks · 13.3 mi
- KLAMATH MARSH RANCHUnderground Storage Tanks · 13.4 mi
- SAND CREEK STATIONUnderground Storage Tanks · 13.4 mi
- MAY-SLADE OIL CO.Underground Storage Tanks · 13.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Klamath 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 Klamath County.
Severity Distribution
across Klamath County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Klamath County, two things run higher than the national average across Klamath County — CAFO (5 sites) and Superfund (7 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.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Klamath 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 Klamath County average
Your land is one point inside Klamath County
Everything above resolves to Klamath County as a whole — a county whose own towns’ 30-year records run 132 days between freezes in Keno to 140 in Falcon Heights. Your parcel sits at one point in that range, not in the middle of it. 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 Klamath County Average
Klamath County Average
- ●USDA Zones 6a, averaged across Klamath County
- ●One soil character for all of Klamath County
- ●Frost dates read at Klamath County's scale: Jun 9 to Sep 3
YOUR Parcel
- ✓Your exact zone, not Klamath County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Klamath County
Pull a site-specific report for your exact address in Klamath County, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Klamath County averages can't show:
We read public map data around Klamath County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Klamath County average
How we know this about Klamath 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 Klamath County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Klamath County
When does frost risk typically end in Klamath County?
The last hard freeze (28°F) in Klamath County typically lands around Jun 9, 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 Jun 30.
How long is the growing season in Klamath County?
Measured between 28°F hard freezes, Klamath County sees about 86 frost-free days — roughly Jun 9 through Sep 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 30 to Aug 20, about 51 days.
Is the soil safe to grow vegetables in Klamath County?
The federal record around Klamath County is a meaningful one — 489 documented sites, mostly Underground Storage Tanks entries (333), the nearest Underground Storage Tanks record about 8.8 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 gardeners stretch the season in Klamath County?
With about 86 frost-free days between hard freezes, Klamath County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 114 to 142 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the Jun 9 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Klamath County's scale — its 6a band and its 86-day season. Your yard writes its own version of Klamath 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 Oregon's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Klamath County’s own scale
9 of the readings below were taken at Klamath County's own scale — its own ~86-day span between 28°F freezes, the 3 most extensive soil series mapped here and 489 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Klamath County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Klamath County's own 28°F hard-freeze dates and its ~86-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Klamath CountyUSDA NRCS SSURGO
- 489 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 8.8 miles outFederal environmental registers
- Klamath County's boundary and the 3,807,930 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~86-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Klamath County spans, Eastern Cascades Slopes and Foothills the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Klamath County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Klamath County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
What this page can’t tell you
- How the season shifts across Klamath County — the ~86 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 Klamath County's 3,807,930 acreswhy one lot differs from the next →
- Which of those 489 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 Klamath Countyread your own land →