Rhea County, in Tennessee, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Rhea County lies within Appalachia — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Rhea County holds more than one microclimate.
Soils and elevations shift across Rhea County, so your frost dates and drainage aren't the county average. 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 Rhea County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Rhea County — the short answer
Rhea County, Tennessee: USDA zone 7a, about 227 days between hard freezes, across 202K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 7
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~227
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 202K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 7a is Rhea County's average, not your lot's — a low corner or a tree line moves it. Against Rhea County's 227-day season, see what your own ground reads.
Heat and winter chill in Rhea County
Across a year, Rhea County accumulates about 3,862 growing degree days above 50°F, about 251 fewer than the middle Tennessee county — ahead of 21 of Tennessee’s 95 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Winter banks about 2,137 hours below 45°F, 78 more than the Tennessee middle of 2,059. Chill is what tells a fruit tree its dormancy is over, and it is set by climate rather than by anything you can build.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Rhea County
Across Rhea County, the ground is predominantly Ultisols, where Lily, Pailo, and Gilpin are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 4.6–6.1, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
11%
Hydric soils
2%
Soil still varies lot by lot — soil types explained.
How the ground varies across Rhea County
The USDA soil survey maps 65% of Rhea County as well drained — but another 28% drains differently: 16% somewhat excessively drained, 11% moderately well drained.
Lily is the most extensive named soil at 24% of mapped acres, then Pailo (13%) and Gilpin (8%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Rhea County
Each reading below is measured for Rhea County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Rhea County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Rhea County runs about pH 4.6–6.1, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredRhea County runs about 227 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
MeasuredRhea County sits in USDA hardiness zone 7a.
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 Rhea County is in
Rhea County spans 2 EPA Level III ecoregions — Ridge and Valley (54%) and Southwestern Appalachians (46%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Rhea County
We scored all 1,086 plants against Rhea County's own USDA zone 7a and its own 227-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Tennessee profile.
Is it too late to plant in Rhea 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 Feb 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 7 — 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 gets applied to farmland in Rhea County
USGS estimates 4,642 lb of Glyphosate on Rhea County farmland in 2019, its largest by weight, ahead of 2,4-d (1,732 lb) and Atrazine (1,024 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Rhea County — and how to grow with it.
We checked the federal record across Rhea County — 164 documented sites across 5 of the 9 source types we track.
The most significant on record: 4 Superfund sites (none NPL-listed). 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 Rhea 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, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Rhea County
Closest first, across Rhea County. Listing isn't leaking, and distance isn't exposure.
- Deli-MartUnderground Storage Tanks · 1.3 mi
- Evensville Country StoreUnderground Storage Tanks · 1.6 mi
- W L Wilkey Service StationUnderground Storage Tanks · 1.8 mi
- Tennessee DotUnderground Storage Tanks · 2.0 mi
- Spring Cty S/sUnderground Storage Tanks · 2.1 mi
- Rhea Co. High SchoolUnderground Storage Tanks · 2.5 mi
- Big Orange Fuel StopUnderground Storage Tanks · 3.0 mi
- Golden Eagle MarketUnderground Storage Tanks · 3.0 mi
- RHEA COUNTY LANDFILL/ISANTEK ENVIRONMENTToxics Release Inventory · 3.5 mi
- United Foods Cumberland FarmUnderground Storage Tanks · 3.9 mi
- Robert LittletonUnderground Storage Tanks · 4.0 mi
- Re:G-013Nitrate · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Rhea County'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 Rhea County.
Total Sites
164
across Rhea County
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
across Rhea County
Severity Distribution
across Rhea County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rhea County, two things run higher than the national average across Rhea County — Superfund (4 sites) and Toxics Release Inventory (19 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Rhea County
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 Rhea County average
Your land is one point inside Rhea County
Everything above resolves to Rhea County as a whole — one PHZM band and one county frost record, read across 202K 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 county 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 county average.
Your Lot vs the Rhea County Average
Rhea County Average
- ●USDA Zones 7a, averaged across Rhea County
- ●One soil character for all of Rhea County
- ●Frost dates read at Rhea County's scale: Mar 25 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Rhea County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Rhea County
Pull a site-specific report for your exact address in Rhea County, Tennessee — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Rhea County averages can't show:
We read public map data around Rhea County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Rhea County average
How we know this about Rhea County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Rhea County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Rhea County
When does frost risk typically end in Rhea County?
The last hard freeze (28°F) in Rhea County typically lands around Mar 25, 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 15.
How long is the growing season in Rhea County?
Measured between 28°F hard freezes, Rhea County sees about 227 frost-free days — roughly Mar 25 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Oct 24, about 192 days.
Is the soil safe to grow vegetables in Rhea County?
The federal record around Rhea County is a meaningful one — 164 documented sites, mostly Underground Storage Tanks entries (112), the nearest Underground Storage Tanks record about 1.3 miles 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.
Everything above is measured at Rhea County's scale — its 7a band and its 227-day season. Your yard writes its own version of Rhea County's numbers: 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 Tennessee's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Rhea County’s own scale
8 of the readings below were taken at Rhea County's own scale — its own ~227-day span between 28°F freezes, the 3 most extensive soil series mapped here and 164 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Rhea County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Rhea County's own 28°F hard-freeze dates and its ~227-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Rhea CountyUSDA NRCS SSURGO
- 164 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.3 miles outFederal environmental registers
- Rhea County's boundary and the 201,916 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~227-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Rhea County spans, Ridge and Valley the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Rhea County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Tennessee grower plans around — written at state scale, so they stay on the state guidefrom Tennessee
What this page can’t tell you
- How the season shifts across Rhea County — the ~227 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Rhea County's 201,916 acreswhy one lot differs from the next →
- Which of those 164 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Rhea Countyread your own land →