Putnam County, in Florida, sits in USDA hardiness zone 9b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit okra, meyer lemon, california poppy, and artichoke — 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, Florida: USDA zone 9b, about 320 days between hard freezes, across 466K acres.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 1
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 18
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~320
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 466K 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 9b is Putnam County's average, not your lot's — a low corner or a tree line moves it. Against Putnam County's 320-day season, see what your own ground reads.
Heat and winter chill in Putnam County
Across a year, Putnam County accumulates about 7,356 growing degree days above 50°F, about 29 fewer than the middle Florida county — ahead of 31 of Florida’s 67 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 94 hours below 45°F, 58 more than the Florida middle of 36. 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 Spodosols, where Myakka, Pomona, and Candler are the most extensive named soil series. The soil is generally poorly drained with a fine sand surface. Topsoil pH runs about 4.8–5.3, very strongly acidic. Rainfall drains through hydrologic group A/D soils.
Soil order
Spodosols
Drainage
Poorly drained
Hydric soils
34%
Soil still varies lot by lot — soil types explained.
How the ground varies across Putnam County
The USDA soil survey maps 33% of Putnam County as poorly drained — but another 55% drains differently: 21% very poorly drained, 13% excessively drained.
Myakka is the most extensive named soil at 12% of mapped acres, then Pomona (9%) and Candler (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 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 poorly drained, in hydrologic group A/D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Putnam County runs about pH 4.8–5.3, 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 320 days between hard freezes — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredPutnam County sits in USDA hardiness zone 9b.
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 sits in the Southern Coastal Plain — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Putnam County
We scored all 1,086 plants against Putnam County's own USDA zone 9b and its own 320-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 Florida 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 Jan 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 18 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
Documented around Putnam County
- monarch butterfly269 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Putnam County
USGS estimates 11,179 lb of 2,4-d on Putnam County farmland in 2019, its largest by weight, ahead of Hexazinone (2,107 lb) and Glyphosate (1,123 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 — 413 documented sites across 6 of the 9 source types we track.
The most significant on record: 5 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 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.
- WEST SIDE BAIT & TACKLEUnderground Storage Tanks · 1.6 mi
- BEN H BAGGS IIIUnderground Storage Tanks · 1.7 mi
- CARTER PROPERTYUnderground Storage Tanks · 2.3 mi
- ST. JOHNS SHIP BUILDING INCBrownfields · 2.3 mi
- CIRCLE K #2722109Underground Storage Tanks · 2.4 mi
- COMMUNITY STORE-FRAVEISUnderground Storage Tanks · 2.5 mi
- TEXGAS CORPUnderground Storage Tanks · 2.6 mi
- BEARS ALUMINUM COUnderground Storage Tanks · 2.6 mi
- A J GIAMMANCO & ASSOC INCBrownfields · 2.8 mi
- DSI FORMS INCBrownfields · 2.8 mi
- SHIRLEY GEORGEUnderground Storage Tanks · 2.9 mi
- JOHNS METALSSuperfund · 3.1 mi
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
413
across Putnam County
Risk Level
Elevated
Highest-severity
5 Superfund sites (none NPL-listed)
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 (4 sites) and Underground Storage Tanks (263 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 466K 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 9b, averaged across Putnam County
- ●One soil character for all of Putnam County
- ●Frost dates read at Putnam County's scale: Feb 1 to Dec 18
YOUR Parcel
- ✓Your exact zone, not Putnam County's 9b
- ✓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, Florida — 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 Feb 1, 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 Feb 22.
How long is the growing season in Putnam County?
Measured between 28°F hard freezes, Putnam County sees about 320 frost-free days — roughly Feb 1 through Dec 18, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 22 to Dec 4, about 285 days.
Is the soil safe to grow vegetables in Putnam County?
The federal record around Putnam County is a meaningful one — 413 documented sites, mostly Underground Storage Tanks entries (263), the nearest Underground Storage Tanks record about 1.6 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 9b band and its 320-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 Florida'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 ~320-day span between 28°F freezes, the 3 most extensive soil series mapped here and 413 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 9bUSDA PHZM 2023
- Putnam County's own 28°F hard-freeze dates and its ~320-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
- 413 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.6 miles outFederal environmental registers
- Putnam County's boundary and the 466,173 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~320-day seasonGrowable Ground crop-matching engine
- Putnam County sitting wholly inside the Southern Coastal PlainUS 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 Florida grower plans around — written at state scale, so they stay on the state guidefrom Florida
What this page can’t tell you
- How the season shifts across Putnam County — the ~320 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 466,173 acreswhy one lot differs from the next →
- Which of those 413 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 →