Johnson County, in Arkansas, sits in USDA hardiness zone 8a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: tomato, peach, muscadine grape, and sweet potato. The site-level story — soil, sun, drainage — decides the rest.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Johnson County holds more than one microclimate.
Soils and elevations shift across Johnson 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
8a
Last Hard Freeze (28°F)
Feb 17
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Dec 10
County normal — light frosts arrive a few weeks earlier
County Area
423K acres
Hardiness Zone Range
Zone maps are averages across Johnson County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Johnson County
Across Johnson County, the ground is predominantly Ultisols, where Nella, Mountainburg, and Linker are the most extensive named soil series. The soil is generally well drained with a stony fine sandy loam surface. Topsoil pH runs about 5.0–5.3, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
23%
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
What Grows in Johnson County
Plants matched to Johnson County's USDA zones 8a — each links to its full growing profile.





Is it too late to plant in Johnson County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Jan 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 10 — 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 Arkansas
What an experienced grower plans around here — each one has a move.

Hot, humid summers drive fungal and bacterial diseases
Morning base-watering, wide spacing, and resistant varieties keep disease manageable — your extension lists what holds up here.

Heavy clay soils in parts of the Ozarks
A raised bed gets you growing this season; compost worked in each fall opens the clay for the long run.

Severe spring storms and hail risk
Keep row cover staged through storm season — five minutes of shelter can save a bed of seedlings from hail.
For cultivar selection, pest pressure, and planting-time guidance specific to Arkansas, the University of Arkansas Cooperative Extension Service is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Johnson County — and how to grow with it.
We checked the federal record across Johnson County — 195 documented sites across 6 of the 9 source types we track.
The most significant on record: 15 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
The federal record across Johnson 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
195
across Johnson County
Risk Level
Moderate
Highest-severity
15 Toxics Release Inventory facilities
Sources Checked
across Johnson County
Severity Distribution
across Johnson County
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Johnson County, two things run higher than the national average — Toxic Release Inventory (15 sites) and Underground Storage Tanks (126 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Johnson 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
Johnson County Average
- ●USDA Zones 8a
- ●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 Johnson County
Pull a site-specific report for your exact address in Johnson County, Arkansas — 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 Johnson County, Arkansas
- USDA Hardiness Zones: 8a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Feb 17 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Dec 10 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~296 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 423K 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 Johnson 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 Johnson County, Arkansas?
Johnson County sits in USDA hardiness zone 8a, 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 Johnson County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Jan 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 10 — 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 Johnson County?
The last hard freeze (28°F) in Johnson County typically lands around Feb 17, 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 Johnson County?
Measured between 28°F hard freezes, Johnson County sees about 296 frost-free days — roughly Feb 17 through Dec 10, 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 Johnson County?
Johnson County's zone 8a supports a wide range — strong performers include Tomato, Peach, Muscadine Grape, Sweet Potato, and Blackberry. 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 Johnson County, really?
Officially, Johnson County sits in USDA zone 8a (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 Johnson County?
The federal record around Johnson County shows 195 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 Johnson County — what should I know before planting?
Start with three facts. Johnson County sits in USDA zone 8a, which sets what survives winter; the last 28°F hard freeze typically clears around Feb 17, with about 296 frost-free days to work with (NOAA 1991–2020 climate normals); and 195 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 Johnson 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 Arkansas's frost window, season length, and soil profile against the plant's real requirements.
