Allen, Kansas, sits in USDA hardiness zone 6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Allen, 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 Allen 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 Allen — soil, climate, flood, and parcel records. How we handle your address.
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Allen — the short answer
Allen, Kansas: USDA zone 6b, about 217 days between hard freezes, across 177 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- 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
- ~217
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 177 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 Allen's average, not your lot's — a low corner or a tree line moves it. Against Allen's 217-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Allen
Each reading below is measured for Allen itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAllen runs about 217 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
MeasuredAllen 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 Allen is in
Allen sits in the Flint Hills — EPA Level III, inside the wider Great Plains. That is read at Allen's own centroid rather than borrowed from Lyon County.
What Grows in Allen
Every plant below cleared Allen's own zone 6b and its 217-day season. Each card opens that plant's Kansas profile. How we score.
Is it too late to plant in Allen?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (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. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
What's on the federal record near Allen
Closest first, within ~10 miles of Allen. Listing isn't leaking, and distance isn't exposure.
- LYON COUNTY HIGHWAY DEPARTMENTUnderground Storage Tanks · 300 ft
- 16S 11E 22ADD 01Nitrate · 0.6 mi
- KEITH CATTLE COCAFO · 0.8 mi
- WHEAT RANCH FEEDLOTCAFO · 1.2 mi
- 16S 11E 21DAA 01Nitrate · 1.3 mi
- 2I FEEDERS LLCCAFO · 2.1 mi
- MUNDY'S SERVICE STATIONUnderground Storage Tanks · 3.7 mi
- 16S 10E 34DDA 01Nitrate · 6.8 mi
- 15S 10E 23DCD 01Nitrate · 7.2 mi
- ADMIRE MAINT. M.P. 147Underground Storage Tanks · 7.4 mi
- FORBES (EX) ATLAS FAC S-5Superfund · 7.5 mi
- 17S 10E 14DA 01Nitrate · 7.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Allen'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 Allen.
Total Sites
30
within ~10 miles of Allen
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Allen
Severity Distribution
within ~10 miles of Allen
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Allen, two things run higher than the national average within ~10 miles of Allen — CAFO (4 sites) and Nitrate (22 sites). That's not a problem with your land — it's information about it.
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 Allen
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 Allen average
Your land is one point inside Allen
Everything above resolves to Allen as a whole — one PHZM band and one 28°F frost record, read across 177 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 Allen Average
Allen Average
- ●USDA Zones 6b, averaged across Allen
- ●One soil character for all of Allen
- ●Frost dates read at Allen's scale: Apr 1 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Allen's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Allen
Pull a site-specific report for your exact address in Allen, Kansas — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Allen averages can't show:
We read public map data around Allen — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Allen average
How we know this about Allen
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 Allen’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 Allen
When does frost risk typically end in Allen?
The last hard freeze (28°F) in Allen typically lands around Apr 1, 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 22.
When is the first frost in Allen?
The first hard freeze (28°F) in Allen 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 217 days after the spring freeze cleared.
How long is the growing season in Allen?
Measured between 28°F hard freezes, Allen sees about 217 frost-free days — roughly Apr 1 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Oct 21, about 182 days.
Is the soil safe to grow vegetables in Allen?
The federal record around Allen is a meaningful one — 30 documented sites, mostly Nitrate entries (22), 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 Allen?
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 Allen's scale — its 6b band and its 217-day season. Your yard writes its own version of Allen'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 Allen’s own scale
6 of the readings below were taken at Allen's own scale — its own ~217-day season between 28°F freezes, the 177 acres it covers and 30 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Allen's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Allen's own 28°F hard-freeze dates, about Apr 1 and Nov 4 and the ~217-day span between themNOAA 1991–2020 Climate Normals
- 30 documented contamination sites on the federal record near Allen, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Allen's boundary and the 177 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~217-day seasonGrowable Ground crop-matching engine
- The ecoregion at Allen's own centroid, the Flint HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Allen's 177 acres read through its county's SSURGO summaryfrom Lyon County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lyon 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 Lyon County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Allen's 177 acreswhy one lot differs from the next →
- Which side of Allen you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 177 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 Allen-wide figureread your own land →
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