Obion County, in Tennessee, sits in USDA hardiness zone 7b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Growers here do well with cabbage, prickly pear, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Obion County lies within the West Tennessee (Gulf Coastal Plain / Loess Plains) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Obion County holds more than one microclimate.
Soils and elevations shift across Obion 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 Obion County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Obion County — the short answer
Obion County, Tennessee: USDA zone 7b, about 231 days between hard freezes, across 349K acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 21
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 7
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~231
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 349K 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 7b is Obion County's average, not your lot's — a low corner or a tree line moves it. Against Obion County's 231-day season, see what your own ground reads.
Heat and winter chill in Obion County
Across a year, Obion County accumulates about 4,252 growing degree days above 50°F, about 139 more than the middle Tennessee county — ahead of 71 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 2,247 hours below 45°F, 188 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 Obion County
Across Obion County, the ground is predominantly Alfisols, where Memphis, Grenada, and Falaya are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 5.3–5.8, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
53%
Hydric soils
19%
Soil still varies lot by lot — soil types explained.
How the ground varies across Obion County
The USDA soil survey maps 31% of Obion County as well drained — but another 66% drains differently: 29% moderately well drained, 20% somewhat poorly drained.
Memphis is the most extensive named soil at 28% of mapped acres, then Grenada (15%) and Falaya (9%).
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 Obion County
Each reading below is measured for Obion 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 Obion 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 Obion County runs about pH 5.3–5.8, 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
Wet ground
MeasuredAbout 19% of Obion County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredObion County runs about 231 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
The kind of country Obion County is in
Obion County spans 2 EPA Level III ecoregions — Mississippi Valley Loess Plains (93%) and Mississippi Alluvial Plain (7%). 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 Obion County
We scored all 1,086 plants against Obion County's own USDA zone 7b and its own 231-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 Obion County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 21 (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. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What gets applied to farmland in Obion County
USGS estimates 159,289 lb of Glyphosate on Obion County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (61,338 lb) and Dicamba (60,606 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 Obion County — and how to grow with it.
We checked the federal record across Obion County — 213 documented sites across 7 of the 9 source types we track.
The most significant on record: 3 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 Obion 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 Obion County
Closest first, across Obion County. Listing isn't leaking, and distance isn't exposure.
- Ob:H-010Nitrate · 0.9 mi
- Osborne Sport CenterUnderground Storage Tanks · 0.9 mi
- Lil General #38Underground Storage Tanks · 1.1 mi
- Storey SawmillUnderground Storage Tanks · 1.5 mi
- Troy Tennessee (qgt) RcagUnderground Storage Tanks · 1.7 mi
- Little General #57Underground Storage Tanks · 1.8 mi
- Barker Bros Waste Inc.Underground Storage Tanks · 1.8 mi
- Town Of TroyUnderground Storage Tanks · 1.9 mi
- Freeman Machinery CoUnderground Storage Tanks · 1.9 mi
- Hanafee Bros. SawmillUnderground Storage Tanks · 1.9 mi
- South Central TroytnmtUnderground Storage Tanks · 1.9 mi
- REPUBLIC SERVICESToxics Release Inventory · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Obion 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 Obion County.
Total Sites
213
across Obion County
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Severity Distribution
across Obion County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Obion County, two things run higher than the national average across Obion County — CAFO (6 sites) and Underground Storage Tanks (156 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Obion 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 Obion County average
Your land is one point inside Obion County
Everything above resolves to Obion County as a whole — one PHZM band and one county frost record, read across 349K 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 Obion County Average
Obion County Average
- ●USDA Zones 7b, averaged across Obion County
- ●One soil character for all of Obion County
- ●Frost dates read at Obion County's scale: Mar 21 to Nov 7
YOUR Parcel
- ✓Your exact zone, not Obion County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Obion County
Pull a site-specific report for your exact address in Obion County, Tennessee — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Obion County averages can't show:
We read public map data around Obion County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Obion County average
How we know this about Obion 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 Obion County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Obion County
When does frost risk typically end in Obion County?
The last hard freeze (28°F) in Obion County typically lands around Mar 21, 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 11.
How long is the growing season in Obion County?
Measured between 28°F hard freezes, Obion County sees about 231 frost-free days — roughly Mar 21 through Nov 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 11 to Oct 24, about 196 days.
Is the soil safe to grow vegetables in Obion County?
The federal record around Obion County is a meaningful one — 213 documented sites, mostly Underground Storage Tanks entries (156), the nearest Nitrate record about 0.9 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 Obion County's scale — its 7b band and its 231-day season. Your yard writes its own version of Obion 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 Obion County’s own scale
8 of the readings below were taken at Obion County's own scale — its own ~231-day span between 28°F freezes, the 3 most extensive soil series mapped here and 213 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Obion County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Obion County's own 28°F hard-freeze dates and its ~231-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Obion CountyUSDA NRCS SSURGO
- 213 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 0.9 miles outFederal environmental registers
- Obion County's boundary and the 348,704 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~231-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Obion County spans, Mississippi Valley Loess Plains the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Obion 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 Obion County — the ~231 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 Obion County's 348,704 acreswhy one lot differs from the next →
- Which of those 213 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 Obion Countyread your own land →