Allen County, in Kentucky, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include pawpaw, tomato, blackberry, and redbud — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Allen County holds more than one microclimate.
Soils and elevations shift across Allen County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Quick Facts
USDA Zones
7a
Last Hard Freeze (28°F)
Feb 21
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Dec 6
County normal — light frosts arrive a few weeks earlier
County Area
220K acres
Hardiness Zone Range
Zone maps are averages across Allen County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Allen County
Across Allen County, the ground is predominantly Alfisols, where Christian, Bedford, and Mountview are the most extensive named soil series. The soil is generally well drained with a gravelly silt loam surface. Topsoil pH runs about 4.8–5.5, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
27%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
What Grows in Allen County
Plants matched to Allen County's USDA zones 7a — each links to its full growing profile.





Is it too late to plant in Allen County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.

Growing Challenges in Kentucky
What an experienced grower plans around here — each one has a move.

Heavy clay soils in the Bluegrass region
Bluegrass clay opens up with steady compost — or start above it in a raised bed and grow while the ground improves.

High humidity promotes fungal diseases
Space wide, water mornings at the base, and favor resistant varieties — your extension's disease-resistant lists earn their keep here.

Karst topography creates drainage unpredictability
Karst ground drains erratically — watch where water goes in a hard rain before siting beds, and mound up where it lingers.
For cultivar selection, pest pressure, and planting-time guidance specific to Kentucky, the University of Kentucky Cooperative Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Allen County — and how to grow with it.
We checked the federal record across Allen County — 174 documented sites across 5 of the 9 source types we track.
The most significant on record: 5 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Allen 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.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Total Sites
174
across Allen County
Risk Level
Moderate
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
across Allen County
Severity Distribution
across Allen County
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Allen County, Nitrate runs higher than the national average — 84 sites nearby. 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.
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 County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Allen County Average
- ●USDA Zones 7a
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Allen County
Pull a site-specific report for your exact address in Allen County, Kentucky — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Allen County, Kentucky
- USDA Hardiness Zones: 7a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Feb 21 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Dec 6 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~288 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 220K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Allen County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Allen County, Kentucky?
Allen County sits in USDA hardiness zone 7a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Allen County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Jan 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
When does frost risk typically end in Allen County?
The last hard freeze (28°F) in Allen County typically lands around Feb 21, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Allen County?
Measured between 28°F hard freezes, Allen County sees about 288 frost-free days — roughly Feb 21 through Dec 6, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Allen County?
Allen County's zone 7a supports a wide range — strong performers include Pawpaw, Tomato, Blackberry, Redbud, and Kentucky Bluegrass. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Allen County, really?
Officially, Allen County sits in USDA zone 7a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Allen County?
The federal record around Allen County shows 174 documented sites — 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.
Just moved to Allen County — what should I know before planting?
Start with three facts. Allen County sits in USDA zone 7a, which sets what survives winter; the last 28°F hard freeze typically clears around Feb 21, with about 288 frost-free days to work with (NOAA 1991–2020 climate normals); and 174 documented sites sit on the federal record — a typical footprint for a growing area, worth a look on the contamination map before food beds. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Allen County average. Your yard writes its own version — 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 Kentucky's frost window, season length, and soil profile against the plant's real requirements.
