Osawatomie, Kansas, sits in USDA hardiness zone 6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with cabbage, hazelnut, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Osawatomie, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Osawatomie lot. 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 Osawatomie — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Osawatomie — the short answer
Osawatomie, Kansas: USDA zone 6b, about 218 days between hard freezes, across 3K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~218
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 Osawatomie's average, not your lot's — a low corner or a tree line moves it. Against Osawatomie's 218-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Osawatomie
Each reading below is measured for Osawatomie itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOsawatomie 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
MeasuredOsawatomie 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 Osawatomie is in
Osawatomie sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Osawatomie's own centroid rather than borrowed from Miami County.
What Grows in Osawatomie
Every plant below cleared Osawatomie's own zone 6b and its 218-day season. Each card opens that plant's Kansas profile. How we score.
Is it too late to plant in Osawatomie?
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 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. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Osawatomie
Survey cells within 31 miles of Osawatomie checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 419 miles off. What to watch for.
What's on the federal record near Osawatomie
Closest first, within ~10 miles of Osawatomie. Listing isn't leaking, and distance isn't exposure.
- MAIN STREET CROSSINGUnderground Storage Tanks · 700 ft
- KENNETH R. JOHNSON, INC.Underground Storage Tanks · 700 ft
- BURNS, C.C.Underground Storage Tanks · 700 ft
- RUSSELL SALV & AUTOBrownfields · 1100 ft
- D & K AUTOMOTIVEUnderground Storage Tanks · 1500 ft
- CASEY'S GENERAL STORE #1977Underground Storage Tanks · 1600 ft
- LYBARGER OILUnderground Storage Tanks · 1600 ft
- UNRR OSAWATOMIEBrownfields · 1700 ft
- D & R SERVICE CENTER INCUnderground Storage Tanks · 1800 ft
- CASEY'S GENERAL STORE - #1191Underground Storage Tanks · 2000 ft
- BURKS AUTO CLINICUnderground Storage Tanks · 2400 ft
- WEAVER ENTERPRIZESUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Osawatomie'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 Osawatomie.
Total Sites
119
within ~10 miles of Osawatomie
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Osawatomie
Severity Distribution
within ~10 miles of Osawatomie
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Osawatomie
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 Osawatomie average
Your land is one point inside Osawatomie
Everything above resolves to Osawatomie as a whole — one PHZM band and one 28°F frost record, read across 3K 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 city 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 local average.
Your Lot vs the Osawatomie Average
Osawatomie Average
- ●USDA Zones 6b, averaged across Osawatomie
- ●One soil character for all of Osawatomie
- ●Frost dates read at Osawatomie's scale: Mar 31 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Osawatomie's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Osawatomie
Pull a site-specific report for your exact address in Osawatomie, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Osawatomie averages can't show:
We read public map data around Osawatomie — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Osawatomie average
How we know this about Osawatomie
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Osawatomie’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Osawatomie
When does frost risk typically end in Osawatomie?
The last hard freeze (28°F) in Osawatomie 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.
When is the first frost in Osawatomie?
The first hard freeze (28°F) in Osawatomie typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 218 days after the spring freeze cleared.
How long is the growing season in Osawatomie?
Measured between 28°F hard freezes, Osawatomie 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 Osawatomie?
The federal record around Osawatomie is a meaningful one — 119 documented sites, mostly Underground Storage Tanks entries (49), the nearest Underground Storage Tanks record about 0.1 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 I protect my plants from frost in Osawatomie?
From about Oct 5 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 4 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Osawatomie's scale — its 6b band and its 218-day season. Your yard writes its own version of Osawatomie's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Osawatomie’s own scale
7 of the readings below were taken at Osawatomie's own scale — its own ~218-day season between 28°F freezes, the 3,299 acres it covers and 119 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Osawatomie's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Osawatomie's own 28°F hard-freeze dates, about Mar 31 and Nov 4 and the ~218-day span between themNOAA 1991–2020 Climate Normals
- 119 documented contamination sites on the federal record near Osawatomie, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Osawatomie's boundary and the 3,299 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~218-day seasonGrowable Ground crop-matching engine
- The ecoregion at Osawatomie's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Osawatomie checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Osawatomie's 3,299 acres read through its county's SSURGO summaryfrom Miami County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Miami County
- The growing challenges every Kansas grower plans around — written at state scale, so they stay on the state guidefrom Kansas
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Miami County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Osawatomie's 3,299 acreswhy one lot differs from the next →
- Which side of Osawatomie you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,299 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Osawatomie-wide figureread your own land →
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