The Flint Hills spans USDA hardiness zones 6a-7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Kansas's Flint Hills hold the largest remaining expanse of intact tallgrass prairie in North America, where thin, cherty limestone soils long favored ranching over the plow, and across its 13 core counties growers work USDA zones 6a to 7a with a frost-free season of roughly 197 to 223 days. Crops well matched to these conditions include tomato, sunflower, buffalo grass, and peach — though what thrives on any one site still turns on its specific soil, sun, and drainage.
The Flint Hills spans Kansas.
Your yard isn't all of the Flint Hills.
The Flint Hills spans USDA zones 6a-7a, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Flint Hills — soil, climate, flood, and parcel records. How we handle your address.
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The Flint Hills — the short answer
The Flint Hills: USDA zones 6a-7a, 197–223 frost-free days, in Kansas.
- USDA zones
- 6a-7a
- USDA PHZM 2023, aggregated over the footprint
- Frost-free season
- 197–223 days
- NOAA Regional Climate Centers ACIS, 1991-2020
- Counties
- 13
- US Census TIGER/Line 2025
- Region type
- County cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. Where a region publishes no measured season, no season figure is shown.
Hardiness Zone Range
What Grows in the Flint Hills
Plants matched to the Flint Hills' USDA zones 6a-7a, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of the Flint Hills
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets the Flint Hills’s USDA zones 6a-7a — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
The ground across the Flint Hills
The USDA soil survey maps this ground county by county. These are those records weighted by land area across 13 member counties — this region’s own profile, not a state figure.
The ground is predominantly Mollisols, at 95% of mapped acres, followed by Alfisols (3%), Entisols (1%) and Vertisols (1%). Five soil orders appear somewhere inside the footprint, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Clime, Irwin, and Labette.
53% of those acres are well drained, and another 36% moderately well drained, 7% somewhat poorly drained. Topsoil pH runs 5.6–7.5 between the lowest and the highest county on record. 45% of the footprint is classed prime farmland.
Soil order
Mollisols
Drainage
Well drained
Topsoil pH
5.6–7.5
Hydric soils
1%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Lyon County holds the most wetland ground here, at 4% — soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the Flint Hills
The soil survey reads this ground county by county, and the readings above are those records summed across the Flint Hills. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records53% of the mapped acres across the Flint Hills are well drained — ground that drains quickly. That is area-weighted across all 13 of its mapped counties.
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
From county recordsTopsoil across the Flint Hills runs pH 5.6–7.5 — near neutral in twelve of its 13 counties.
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
Safe to Grow Here?
What the federal record shows across the Flint Hills — and how to grow with it.
Across the Flint Hills' 13 counties the federal record holds 3,635 documented sites, mostly Nitrate (1,988), Underground Storage Tanks (944) and Brownfields (555). The heaviest single county is Butler County, with 1,225.
That is a regional count, not a reading of any one lot — proximity to a documented site is information, not a diagnosis. Open the map outlined to the Flint Hills to see which records sit where you actually grow.
Sources Checked
Summed across the 13 counties in the Flint Hills
A note from Gnorman
What an experienced grower watches for around here
In and around the Flint Hills, two things run higher than the national average across the 13 counties in the Flint Hills — Nitrate (1,988 sites) and CAFO (41 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the Flint Hills
Everything above resolves to the Flint Hills as a whole — a footprint spanning USDA zones 6a-7a. Your parcel sits in exactly one of them. 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 region 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 regional average.
Your Lot vs the Flint Hills Average
Flint Hills Average
- ●USDA Zones 6a-7a, averaged across Flint Hills
- ●One soil character for all of Flint Hills
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Flint Hills' 6a-7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Flint Hills
Pull a site-specific report for your exact address in the Flint Hills — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Flint Hills averages can't show:
We read public map data around The Flint Hills — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Flint Hills average
How we know this about the Flint Hills
The boundary: a cluster of neighboring counties. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the counties inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about the Flint Hills
What hardiness zone is the Flint Hills?
The Flint Hills spans USDA hardiness zones 6a-7a, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's counties. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the Flint Hills?
Measured between 28°F hard freezes, the Flint Hills' counties mostly run 209 to 220 frost-free days, median 214 (NOAA Regional Climate Centers ACIS, 1991–2020, over 13 member counties). That 11-day spread is the honest read — no single season describes 13 counties, and each county guide below carries its own.
When does frost risk end in the Flint Hills?
Across the Flint Hills, the middle half of member counties see their last 28°F hard freeze between Apr 1 and Apr 3 (median Apr 3), and their first fall freeze between Oct 29 and Nov 7. Those are hard freezes, not the last light frost: tender transplants wait for about Apr 24, and elevation decides which end of a 2-day spread you garden in.
What grows well in the Flint Hills?
The Flint Hills' conditions suit plants such as Tomato, Sunflower, Buffalo Grass, Peach, Blackberry. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is the Flint Hills defined?
The Flint Hills is defined here as a curated cluster of 13 neighboring counties that share a growing character. Growing regions have no official boundary, so this footprint is our published one — every county in it is named on this page.
Which states does the Flint Hills cover?
The Flint Hills spans Kansas. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
High Plains, Southeast Kansas / Cherokee Lowlands (Ozark Border), Wichita / South-Central Kansas (Arkansas River Lowlands), and Greater Kansas City Metro (Kansas Side) share at least one state with the Flint Hills. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at the Flint Hills’s own scale
6 of the readings below were taken at the Flint Hills' own scale — the zone 6a-7a band across its footprint, a median 214-day season across its 13 counties and 3,635 documented federal contamination records across its 13 counties, 1,225 of them in Butler County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 6a-7a aggregated across all 13 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 13 counties this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The 28°F season across the footprint — the middle half of its 13 counties run 209 to 220 frost-free days, median 214NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 3,635 documented federal contamination records across its 13 counties, 1,225 of them in Butler County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 95% Mollisols, topsoil pH 5.6–7.5, area-weighted across its 13 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 6a-7afrom Kansas
What this page can’t tell you
- Which end of the 11-day range your ground sits at — 209 days at one extreme, 220 at the other, decided mostly by elevationfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore the Flint Hills
State growing guides
Counties in this region
Other growing regions across Kansas
A semi-arid shortgrass tableland of deep soils and big sky, where wind, low rainfall, and irrigation shape dryland wheat, sorghum, and resilient gardens.
The warmest, wettest, longest-season corner of Kansas. Cherokee and Crawford counties run zone 7a with about 231 frost-free days — roughly three weeks past the state's midsection and over a month longer than the arid High Plains — and the whole cluster sits at 219–231 days (verified, api/data/county_data.json). This is Ozark-border ground: acidic, timbered soils and coal strip-pit lake country on the tip of the Springfield Plateau that pushes into Cherokee County, not the thin alkaline limestone rangeland of the Flint Hills or the dryland wheat-and-sorghum semi-arid west. A grower in Pittsburg or Columbus gardens a longer, more humid, more acidic season than the statewide Kansas page implies — favoring tree fruit, brambles, and heat-loving crops that want a full season and soil that leans acid.
South-central Kansas's warm sandy tier — the Arkansas River Lowlands, where alluvial sand plains drain and warm faster than the loess and limestone prairie around them. The Wichita core runs zone 7a with roughly 226 frost-free days, the longest, warmest growing window in central Kansas and genuinely different soil to dig than the Flint Hills to the east.
The Kansas half of the Kansas City metro — Johnson, Wyandotte, Leavenworth, and Miami counties, from Overland Park and Olathe to Kansas City, KS. What sets this page apart isn't a different climate — it's a split city. 'Kansas City planting zone' is one search for two states, and this is the KS-side answer. Gardeners here sit in USDA zone 6b with a roughly 215–223-day growing season — last spring frost around March 30–April 1, first fall frost near November 2–8 — the same eastern-Kansas rhythm that governs the whole metro. The state line is a jurisdictional edge, not a climate one, so plan by the season, not the county sign.