Olathe, Kansas, sits in USDA hardiness zone 6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Olathe, 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 Olathe 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 Olathe — soil, climate, flood, and parcel records. How we handle your address.
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Olathe — the short answer
Olathe, Kansas: USDA zone 6b, about 223 days between hard freezes, across 41K acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~223
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 41K 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 Olathe's average, not your lot's — a low corner or a tree line moves it. Against Olathe's 223-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Olathe
Each reading below is measured for Olathe itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOlathe runs about 223 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
MeasuredOlathe 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 Olathe is in
Olathe sits in the Central Irregular Plains — EPA Level III, inside the wider Great Plains. That is read at Olathe's own centroid rather than borrowed from Johnson County.
What Grows in Olathe
Every plant below cleared Olathe's own zone 6b and its 223-day season. Each card opens that plant's Kansas profile. How we score.
Is it too late to plant in Olathe?
Almost never — the real question is what to plant next. 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 Nov 8 — 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 Olathe
Survey cells within 31 miles of Olathe checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 399 miles off. What to watch for.
What's on the federal record near Olathe
Closest first, within ~10 miles of Olathe. Listing isn't leaking, and distance isn't exposure.
- JOHNSON CO COURTHOUSEUnderground Storage Tanks · 200 ft
- JOHNSON CO ADMINISTRATION BLDGUnderground Storage Tanks · 200 ft
- FURNITURE KNOWLEDGEBrownfields · 250 ft
- OLATHE ADULT DETENTION CENTERUnderground Storage Tanks · 350 ft
- JOHNSON CNTY COURTHOUSEBrownfields · 600 ft
- SPRUYTTE 66 SERVICEUnderground Storage Tanks · 600 ft
- DALES BODY SHOPBrownfields · 600 ft
- BOBS SERVICEUnderground Storage Tanks · 650 ft
- OLATHE, CITY OFUnderground Storage Tanks · 750 ft
- OLATHE CITY HALL EASTUnderground Storage Tanks · 800 ft
- OLATHE CITY HALL WESTUnderground Storage Tanks · 800 ft
- BLAIRS AUTOMOTIVEBrownfields · 900 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Olathe'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 Olathe.
Sources Checked
within ~10 miles of Olathe
Severity Distribution
within ~10 miles of Olathe
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Olathe, two things run higher than the national average within ~10 miles of Olathe — Brownfields (629 sites) and Toxics Release Inventory (77 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Olathe
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 Olathe average
Your land is one point inside Olathe
Everything above resolves to Olathe as a whole — one PHZM band and one 28°F frost record, read across 41K 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 Olathe Average
Olathe Average
- ●USDA Zones 6b, averaged across Olathe
- ●One soil character for all of Olathe
- ●Frost dates read at Olathe's scale: Mar 30 to Nov 8
YOUR Parcel
- ✓Your exact zone, not Olathe's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Olathe
Pull a site-specific report for your exact address in Olathe, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Olathe averages can't show:
We read public map data around Olathe — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Olathe average
How we know this about Olathe
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 Olathe’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 Olathe
When does frost risk typically end in Olathe?
The last hard freeze (28°F) in Olathe 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.
When is the first frost in Olathe?
The first hard freeze (28°F) in Olathe typically arrives around Nov 8, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 25, so the watching starts about Oct 9 — about 223 days after the spring freeze cleared.
How long is the growing season in Olathe?
Measured between 28°F hard freezes, Olathe sees about 223 frost-free days — roughly Mar 30 through Nov 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 25, about 188 days.
Is the soil safe to grow vegetables in Olathe?
The federal record around Olathe is a meaningful one — 1,201 documented sites, mostly Brownfields entries (629), the nearest Underground Storage Tanks record under a tenth of a mile 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 Olathe?
From about Oct 9 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 8 (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 8. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Olathe's scale — its 6b band and its 223-day season. Your yard writes its own version of Olathe'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 Olathe’s own scale
7 of the readings below were taken at Olathe's own scale — its own ~223-day season between 28°F freezes, the 41,222 acres it covers and 1,201 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Olathe's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Olathe's own 28°F hard-freeze dates, about Mar 30 and Nov 8 and the ~223-day span between themNOAA 1991–2020 Climate Normals
- 1,201 documented contamination sites on the federal record near Olathe, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Olathe's boundary and the 41,222 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~223-day seasonGrowable Ground crop-matching engine
- The ecoregion at Olathe's own centroid, the Central Irregular PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Olathe 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 Olathe's 41,222 acres read through its county's SSURGO summaryfrom Johnson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Johnson 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 Johnson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Olathe's 41,222 acreswhy one lot differs from the next →
- Which side of Olathe you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 41,222 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Olathe-wide figureread your own land →