What Grows in Union County, Kentucky

USDA Zones 7a · 219K acres

Union County, in Kentucky, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.

On paper, pawpaw, tomato, blackberry, and redbud all suit these conditions — on the ground, soil, sun, and drainage make the final call.

Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals

Score your parcel · free

Union County holds more than one microclimate.

Soils and elevations shift across Union 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 27

County normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Dec 3

County normal — light frosts arrive a few weeks earlier

County Area

219K acres

Hardiness Zone Range

7a7a
3a (Cold)13b (Hot)

Zone maps are averages across Union County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil in Union County

Across Union County, the ground is predominantly Alfisols, where Alford, Patton, and Uniontown are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 5.9–6.5, slightly acidic. Rainfall drains through hydrologic group B soils.

Soil order

Alfisols

Drainage

Well drained

Prime farmland

32%

Hydric soils

16%

Soil still varies lot by lot — soil types explained.

Is it too late to plant in Union County?

Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 3 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

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 Union County — and how to grow with it.

Federal record: Elevated

We checked the federal record across Union County116 documented sites across 6 of the 9 source types we track.

The most significant on record: 1 Superfund site. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

There's a meaningful federal record across Union County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.

Sources: EPA, USGS1.8M 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

116

across Union County

Risk Level

Elevated

Highest-severity

1 Superfund site

Severity Distribution

across Union County

High3Moderate36Low77

Highest-Severity Sites

Morganfield Water Works
PFAS Sampling · PFAS Detected
Union County Water District
PFAS Sampling · PFAS Detected
Universal Plating
Superfund · Superfund (Non-NPL)
Buds Country Corner
Underground Storage Tanks · Open UST(S)
Caseys General Store #3379
Underground Storage Tanks · Open UST(S)

A note from Gnorman

What an experienced grower watches for around here

In and around Union County, two things run higher than the national average — PFAS (3 sites) and Underground Storage Tanks (84 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.

Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.

Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.

Use raised beds with imported soil — this eliminates the primary soil-contact pathway.

Free Report

Check your specific parcel in Union 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:

Your soil pHYour frost-free daysYour sun & shade

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

Union 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

Free Report

Read your parcel in Union County

Pull a site-specific report for your exact address in Union County, Kentucky — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

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 Union County, Kentucky

  • USDA Hardiness Zones: 7a (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Feb 27 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Dec 3 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~279 (county normal, NOAA 1991–2020 Climate Normals)
  • County Land Area: 219K 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 Union 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 Union County, Kentucky?

Union 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 Union County?

Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Jan 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 3 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

When does frost risk typically end in Union County?

The last hard freeze (28°F) in Union County typically lands around Feb 27, 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 Union County?

Measured between 28°F hard freezes, Union County sees about 279 frost-free days — roughly Feb 27 through Dec 3, 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 Union County?

Union 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 Union County, really?

Officially, Union 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 Union County?

The federal record around Union County is a meaningful one — 116 documented sites — 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.

Just moved to Union County — what should I know before planting?

Start with three facts. Union County sits in USDA zone 7a, which sets what survives winter; the last 28°F hard freeze typically clears around Feb 27, with about 279 frost-free days to work with (NOAA 1991–2020 climate normals); and 116 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.

Everything on this page is a Union 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.