Putnam County, in Tennessee, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit cabbage, hazelnut, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Putnam County holds more than one microclimate.
Soils and elevations shift across Putnam 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 Putnam County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Putnam County — the short answer
Putnam County, Tennessee: USDA zone 7a, about 217 days between hard freezes, across 257K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~217
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 257K 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 Putnam County's average, not your lot's — a low corner or a tree line moves it. Against Putnam County's 217-day season, see what your own ground reads.
Heat and winter chill in Putnam County
Across a year, Putnam County accumulates about 3,868 growing degree days above 50°F, about 245 fewer than the middle Tennessee county — ahead of 23 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 2,218 hours below 45°F, 159 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 Putnam County
Across Putnam County, the ground is predominantly Ultisols, where Christian, Hawthorne, and Mountview are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 5.0–5.6, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
21%
Hydric soils
3%
Soil still varies lot by lot — soil types explained.
How the ground varies across Putnam County
The USDA soil survey maps 64% of Putnam County as well drained — but another 31% drains differently: 18% somewhat excessively drained, 9% moderately well drained.
Christian is the most extensive named soil at 7% of mapped acres, then Hawthorne (7%) and Mountview (7%).
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 Putnam County
Each reading below is measured for Putnam 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 Putnam 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 Putnam County runs about pH 5.0–5.6, 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
MeasuredPutnam County runs about 217 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
MeasuredPutnam 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 Putnam County is in
Putnam County spans 2 EPA Level III ecoregions — Interior Plateau (63%) and Southwestern Appalachians (37%). 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 Putnam County
We scored all 1,086 plants against Putnam County's own USDA zone 7a and its own 217-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 Putnam County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — 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.
Documented around Putnam County
- Japanese beetle1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Putnam County
USGS estimates 21,006 lb of 2,4-d on Putnam County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (2,945 lb) and Metolachlor-s (2,305 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 Putnam County — and how to grow with it.
We checked the federal record across Putnam County — 343 documented sites across 5 of the 9 source types we track.
The most significant on record: 20 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Putnam 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 Putnam County
Closest first, across Putnam County. Listing isn't leaking, and distance isn't exposure.
- Putnam County Highway DepartmentUnderground Storage Tanks · 900 ft
- School Bus Garage-Transportation DepartmentUnderground Storage Tanks · 950 ft
- LOWE'S OF COOKEVILLE #578Brownfields · 1200 ft
- John E Mccluen CoUnderground Storage Tanks · 1500 ft
- Class A Oil And Lube CenterUnderground Storage Tanks · 1500 ft
- I-40 Shell MarketUnderground Storage Tanks · 1600 ft
- Ultra Pro Auto WashUnderground Storage Tanks · 1600 ft
- South Jefferson ChevronUnderground Storage Tanks · 1700 ft
- Murphy USA #7008Underground Storage Tanks · 1800 ft
- Scot Market # 49Underground Storage Tanks · 1900 ft
- Cookeville MarathonUnderground Storage Tanks · 2000 ft
- WALMART SUPERCENTER #657Brownfields · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Putnam 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 Putnam County.
Total Sites
343
across Putnam County
Risk Level
Elevated
Highest-severity
20 Toxics Release Inventory facilities
Sources Checked
across Putnam County
Severity Distribution
across Putnam County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Putnam County, two things run higher than the national average across Putnam County — PFAS (5 sites) and Underground Storage Tanks (255 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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.
Check your specific parcel in Putnam 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 Putnam County average
Your land is one point inside Putnam County
Everything above resolves to Putnam County as a whole — one PHZM band and one county frost record, read across 257K 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 Putnam County Average
Putnam County Average
- ●USDA Zones 7a, averaged across Putnam County
- ●One soil character for all of Putnam County
- ●Frost dates read at Putnam County's scale: Mar 31 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Putnam County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Putnam County
Pull a site-specific report for your exact address in Putnam County, Tennessee — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Putnam County averages can't show:
We read public map data around Putnam County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Putnam County average
How we know this about Putnam 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 Putnam County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Putnam County
When does frost risk typically end in Putnam County?
The last hard freeze (28°F) in Putnam County typically lands around Mar 31, 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 21.
How long is the growing season in Putnam County?
Measured between 28°F hard freezes, Putnam County sees about 217 frost-free days — roughly Mar 31 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 20, about 182 days.
Is the soil safe to grow vegetables in Putnam County?
The federal record around Putnam County is a meaningful one — 343 documented sites, mostly Underground Storage Tanks entries (255), the nearest Underground Storage Tanks record about 0.2 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 Putnam County's scale — its 7a band and its 217-day season. Your yard writes its own version of Putnam 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 Putnam County’s own scale
9 of the readings below were taken at Putnam County's own scale — its own ~217-day span between 28°F freezes, the 3 most extensive soil series mapped here and 343 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Putnam County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Putnam County's own 28°F hard-freeze dates and its ~217-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Putnam CountyUSDA NRCS SSURGO
- 343 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.2 miles outFederal environmental registers
- Putnam County's boundary and the 256,708 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~217-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Putnam County spans, Interior Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Putnam County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Putnam 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 Putnam County — the ~217 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 Putnam County's 256,708 acreswhy one lot differs from the next →
- Which of those 343 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 Putnam Countyread your own land →