Osage County, in Kansas, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Osage County holds more than one microclimate.
Soils and elevations shift across Osage 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 Osage County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Osage County — the short answer
Osage County, Kansas: USDA zone 6b, about 218 days between hard freezes, across 452K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~218
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 452K 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 6b is Osage County's average, not your lot's — a low corner or a tree line moves it. Against Osage County's 218-day season, see what your own ground reads.
Heat in Osage County
Across a year, Osage County accumulates about 3,855 growing degree days above 50°F, about 22 more than the middle Kansas county — ahead of 55 of Kansas’s 105 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 Osage County
Across Osage County, the ground is predominantly Mollisols, where Eram, Kenoma, and Summit are the most extensive named soil series. The soil is generally moderately well drained with a silty clay loam surface. Topsoil pH runs about 6.1–6.5, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Mollisols
Drainage
Moderately well drained
Prime farmland
53%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Osage County
The USDA soil survey maps 53% of Osage County as moderately well drained — but another 44% drains differently: 30% well drained, 11% somewhat poorly drained.
Eram is the most extensive named soil at 22% of mapped acres, then Kenoma (18%) and Summit (13%).
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 Osage County
Each reading below is measured for Osage 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 Osage County are moderately well drained, in hydrologic group D — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Osage County runs about pH 6.1–6.5, 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
MeasuredOsage County runs about 218 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
MeasuredOsage County sits in USDA hardiness zone 6b.
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 Osage County is in
Osage County sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Osage County
We scored all 1,086 plants against Osage County's own USDA zone 6b and its own 218-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 Kansas profile.
Is it too late to plant in Osage County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Osage County
Survey cells within 31 miles of Osage County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 448 miles off. What to watch for.
- monarch butterfly963 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Osage County
USGS estimates 152,593 lb of Glyphosate on Osage County farmland in 2019, its largest by weight, ahead of Acephate (92,361 lb) and Metolachlor & Metolachlor-s (88,979 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 Osage County — and how to grow with it.
We checked the federal record across Osage County — 151 documented sites across 6 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 Osage 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 Osage County
Closest first, across Osage County. Listing isn't leaking, and distance isn't exposure.
- 16S 16E 18CC 01Nitrate · 0.9 mi
- SPORTS MARTUnderground Storage Tanks · 1.9 mi
- POMONA LAKE AIRPORTUnderground Storage Tanks · 2.2 mi
- SALT CREEK AUTO BODYBrownfields · 2.3 mi
- D'S MINI MART #3Underground Storage Tanks · 2.6 mi
- FORBES (EX) SURVIVAL TRAINING ANNEXSuperfund · 2.6 mi
- OSAGE COUNTY ROAD & BRIDGEUnderground Storage Tanks · 2.7 mi
- OSAGE COUNTY HIGHWAY DEPTUnderground Storage Tanks · 2.7 mi
- LYNDON TOWN PUMPUnderground Storage Tanks · 2.8 mi
- J & T SERVICEUnderground Storage Tanks · 3.0 mi
- ROMINE TEXACOUnderground Storage Tanks · 3.1 mi
- CASEY'S GENERAL STORE #3248Underground Storage Tanks · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Osage 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 Osage County.
Total Sites
151
across Osage County
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
across Osage County
Severity Distribution
across Osage County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Osage County, Nitrate runs higher than the national average — 60 sites across Osage County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Osage 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 Osage County average
Your land is one point inside Osage County
Everything above resolves to Osage County as a whole — one PHZM band and one county frost record, read across 452K 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 Osage County Average
Osage County Average
- ●USDA Zones 6b, averaged across Osage County
- ●One soil character for all of Osage County
- ●Frost dates read at Osage County's scale: Mar 31 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Osage County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Osage County
Pull a site-specific report for your exact address in Osage County, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Osage County averages can't show:
We read public map data around Osage County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Osage County average
How we know this about Osage 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 Osage County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Osage County
When does frost risk typically end in Osage County?
The last hard freeze (28°F) in Osage County typically lands around Mar 31, 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 21.
How long is the growing season in Osage County?
Measured between 28°F hard freezes, Osage County sees about 218 frost-free days — roughly Mar 31 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 21, about 183 days.
Is the soil safe to grow vegetables in Osage County?
The federal record around Osage County is a meaningful one — 151 documented sites, mostly Underground Storage Tanks entries (63), the nearest Nitrate record about 0.9 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 Osage County's scale — its 6b band and its 218-day season. Your yard writes its own version of Osage 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 Kansas's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Osage County’s own scale
9 of the readings below were taken at Osage County's own scale — its own ~218-day span between 28°F freezes, the 3 most extensive soil series mapped here and 151 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Osage County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Osage County's own 28°F hard-freeze dates and its ~218-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Osage CountyUSDA NRCS SSURGO
- 151 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 0.9 miles outFederal environmental registers
- Osage County's boundary and the 451,524 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~218-day seasonGrowable Ground crop-matching engine
- Osage County sitting wholly inside the Central Irregular PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Osage County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Osage County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Kansas grower plans around — written at state scale, so they stay on the state guidefrom Kansas
What this page can’t tell you
- How the season shifts across Osage County — the ~218 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 Osage County's 451,524 acreswhy one lot differs from the next →
- Which of those 151 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 Osage Countyread your own land →