Harper County, in Kansas, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
A short list that earns its place here — cabbage, hazelnut, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Harper County lies within the Wichita / South-Central Kansas (Arkansas River Lowlands) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Harper County holds more than one microclimate.
Soils and elevations shift across Harper 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 Harper County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Harper County — the short answer
Harper County, Kansas: USDA zone 7a, about 227 days between hard freezes, across 513K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~227
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 513K 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 7a is Harper County's average, not your lot's — a low corner or a tree line moves it. Against Harper County's 227-day season, see what your own ground reads.
Heat in Harper County
Across a year, Harper County accumulates about 4,368 growing degree days above 50°F, about 535 more than the middle Kansas county — ahead of every other Kansas county. 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 Harper County
Across Harper County, the ground is predominantly Mollisols, where Grant, Shellabarger, and Nalim are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.2–7.0, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
67%
Hydric soils
3%
Soil still varies lot by lot — soil types explained.
How the ground varies across Harper County
The USDA soil survey maps 84% of Harper County as well drained — but another 16% drains differently: 7% moderately well drained, 4% somewhat excessively drained.
Grant is the most extensive named soil at 11% of mapped acres, then Shellabarger (10%) and Nalim (10%).
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 Harper County
Each reading below is measured for Harper 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 Harper County are well drained, in hydrologic group C — 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 Harper County runs about pH 6.2–7.0, 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
Season length
MeasuredHarper County runs about 227 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
MeasuredHarper County sits in USDA hardiness zone 7a.
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 Harper County is in
Harper County sits in the Central Great Plains — EPA Level III, inside the wider Great Plains. One consistent ecological setting across the whole county.
What Grows in Harper County
We scored all 1,086 plants against Harper County's own USDA zone 7a and its own 227-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 Harper County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Harper County
- monarch butterfly412 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Harper County
USGS estimates 97,570 lb of Glyphosate on Harper County farmland in 2019, its largest by weight, ahead of 2,4-d (34,142 lb) and Atrazine (27,448 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 Harper County — and how to grow with it.
We checked the federal record across Harper County — 164 documented sites across 4 of the 9 source types we track.
The most significant on record: 7 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Harper County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Harper County
Closest first, across Harper County. Listing isn't leaking, and distance isn't exposure.
- IRELAND-SMITH INCBrownfields · 1.5 mi
- BTB AIRCRAFT SVC IBrownfields · 2.4 mi
- CITY OF ANTHONYUnderground Storage Tanks · 2.5 mi
- KANSAS DEPT OF TRANSPORTATIONUnderground Storage Tanks · 2.6 mi
- SHEPHERD OIL COMPANY, LLCUnderground Storage Tanks · 2.6 mi
- J & M PROPERTIES OF KS, LLCUnderground Storage Tanks · 2.8 mi
- FARMERS OIL COMPANY INCBrownfields · 2.9 mi
- FARMERS OIL COMPANY INCUnderground Storage Tanks · 2.9 mi
- SHEPHERD FOOD MARTUnderground Storage Tanks · 2.9 mi
- ANTHONY, CITY OFUnderground Storage Tanks · 2.9 mi
- CENTRAL ELECTROPOLISHING CO (CELCO)Toxics Release Inventory · 2.9 mi
- CENTRAL ELECTROPOLISHING CO (CELCO)Brownfields · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Harper 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 Harper County.
Total Sites
164
across Harper County
Risk Level
Moderate
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
across Harper County
Severity Distribution
across Harper County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Harper County, Nitrate runs higher than the national average — 80 sites across Harper 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 Harper 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 Harper County average
Your land is one point inside Harper County
Everything above resolves to Harper County as a whole — one PHZM band and one county frost record, read across 513K 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 Harper County Average
Harper County Average
- ●USDA Zones 7a, averaged across Harper County
- ●One soil character for all of Harper County
- ●Frost dates read at Harper County's scale: Mar 28 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Harper County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Harper County
Pull a site-specific report for your exact address in Harper County, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Harper County averages can't show:
We read public map data around Harper County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Harper County average
How we know this about Harper 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 Harper County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Harper County
When does frost risk typically end in Harper County?
The last hard freeze (28°F) in Harper County typically lands around Mar 28, 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 18.
How long is the growing season in Harper County?
Measured between 28°F hard freezes, Harper County sees about 227 frost-free days — roughly Mar 28 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Oct 27, about 192 days.
Is the soil safe to grow vegetables in Harper County?
The federal record around Harper County shows 164 documented sites, mostly Nitrate entries (80), the nearest Brownfields record about 1.5 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
Everything above is measured at Harper County's scale — its 7a band and its 227-day season. Your yard writes its own version of Harper 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 Harper County’s own scale
9 of the readings below were taken at Harper County's own scale — its own ~227-day span between 28°F freezes, the 3 most extensive soil series mapped here and 164 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Harper County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Harper County's own 28°F hard-freeze dates and its ~227-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Harper CountyUSDA NRCS SSURGO
- 164 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 1.5 miles outFederal environmental registers
- Harper County's boundary and the 512,815 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~227-day seasonGrowable Ground crop-matching engine
- Harper County sitting wholly inside the Central Great PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Harper County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Harper 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 Harper County — the ~227 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 Harper County's 512,815 acreswhy one lot differs from the next →
- Which of those 164 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 Harper Countyread your own land →