Simpson, Kansas, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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 Simpson, 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 Simpson 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 Simpson — soil, climate, flood, and parcel records. How we handle your address.
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Simpson — the short answer
Simpson, Kansas: USDA zone 6b, about 206 days between hard freezes, across 164 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~206
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 164 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 Simpson's average, not your lot's — a low corner or a tree line moves it. Against Simpson's 206-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Simpson
Each reading below is measured for Simpson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSimpson runs about 206 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
MeasuredSimpson 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 Simpson is in
Simpson sits in the Central Great Plains — EPA Level III, inside the wider Great Plains. That is read at Simpson's own centroid rather than borrowed from Mitchell County.
What Grows in Simpson
Every plant below cleared Simpson's own zone 6b and its 206-day season. Each card opens that plant's Kansas profile. How we score.
Is it too late to plant in Simpson?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — 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.
What's on the federal record near Simpson
Closest first, within ~10 miles of Simpson. Listing isn't leaking, and distance isn't exposure.
- 08S 06W 01ADD 01Nitrate · 1200 ft
- BERGMANN PROPERTYUnderground Storage Tanks · 1400 ft
- 08S 06W 01BDA 01Nitrate · 1800 ft
- 08S 06W 01CBC 01Nitrate · 0.7 mi
- 08S 05W 07CB 01Nitrate · 1.2 mi
- 07S 06W 36AAB 01Nitrate · 1.4 mi
- SIMPSON KSUnderground Storage Tanks · 1.5 mi
- 07S 06W 24CDD 01Nitrate · 2.6 mi
- 07S 06W 27CDD 01Nitrate · 2.8 mi
- ASHERVILLE GRAIN COMPANYUnderground Storage Tanks · 2.8 mi
- 08S 05W 17DCA 01Nitrate · 3.0 mi
- GJL FARMS, LLC - ASHERVILLECAFO · 3.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Simpson'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 Simpson.
Total Sites
95
within ~10 miles of Simpson
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Simpson
Severity Distribution
within ~10 miles of Simpson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Simpson, two things run higher than the national average within ~10 miles of Simpson — CAFO (3 sites) and Nitrate (68 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Simpson
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 Simpson average
Your land is one point inside Simpson
Everything above resolves to Simpson as a whole — one PHZM band and one 28°F frost record, read across 164 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 Simpson Average
Simpson Average
- ●USDA Zones 6b, averaged across Simpson
- ●One soil character for all of Simpson
- ●Frost dates read at Simpson's scale: Apr 6 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Simpson's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Simpson
Pull a site-specific report for your exact address in Simpson, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Simpson averages can't show:
We read public map data around Simpson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Simpson average
How we know this about Simpson
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 Simpson’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 Simpson
When does frost risk typically end in Simpson?
The last hard freeze (28°F) in Simpson typically lands around Apr 6, 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 27.
When is the first frost in Simpson?
The first hard freeze (28°F) in Simpson typically arrives around Oct 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 15, so the watching starts about Sep 29 — about 206 days after the spring freeze cleared.
How long is the growing season in Simpson?
Measured between 28°F hard freezes, Simpson sees about 206 frost-free days — roughly Apr 6 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 27 to Oct 15, about 171 days.
Is the soil safe to grow vegetables in Simpson?
The federal record around Simpson shows 95 documented sites, mostly Nitrate entries (68), the nearest Nitrate record about 0.2 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.
How do I protect my plants from frost in Simpson?
From about Sep 29 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 Oct 29 (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 Oct 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Simpson's scale — its 6b band and its 206-day season. Your yard writes its own version of Simpson'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 Simpson’s own scale
6 of the readings below were taken at Simpson's own scale — its own ~206-day season between 28°F freezes, the 164 acres it covers and 95 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Simpson's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Simpson's own 28°F hard-freeze dates, about Apr 6 and Oct 29 and the ~206-day span between themNOAA 1991–2020 Climate Normals
- 95 documented contamination sites on the federal record near Simpson, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Simpson's boundary and the 164 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~206-day seasonGrowable Ground crop-matching engine
- The ecoregion at Simpson's own centroid, the Central Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Simpson's 164 acres read through its county's SSURGO summaryfrom Mitchell County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Mitchell 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 Mitchell County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Simpson's 164 acreswhy one lot differs from the next →
- Which side of Simpson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 164 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 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 Simpson-wide figureread your own land →
More in Kansas
Wider growing context
What grows across KansasSimpson sits outside our named growing regions, so Kansas as a whole is its closest context here.
Nearby growing guides