Polk County, in Florida, sits in USDA hardiness zone 10a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Crops well matched to these conditions include okra, meyer lemon, california poppy, and artichoke — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Polk County lies within the Central Florida Ridge — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Polk County holds more than one microclimate.
Soils and elevations shift across Polk 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 Polk County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Polk County — the short answer
Polk County, Florida: USDA zone 10a, about 332 days between hard freezes, across 1.2M acres.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 22
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 20
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~332
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.2M 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 10a is Polk County's average, not your lot's — a low corner or a tree line moves it. Against Polk County's 332-day season, see what your own ground reads.
Heat and winter chill in Polk County
Across a year, Polk County accumulates about 8,528 growing degree days above 50°F, about 1,143 more than the middle Florida county — ahead of 53 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 0 hours below 45°F, 36 fewer 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 Polk County
Across Polk County, the ground is predominantly Entisols, where Candler, Pomona, and Smyrna are the most extensive named soil series. The soil is generally poorly drained with a fine sand surface. Topsoil pH runs about 4.8–5.7, strongly acidic. Rainfall drains through hydrologic group A/D soils.
Soil order
Entisols
Drainage
Poorly drained
Hydric soils
35%
Soil still varies lot by lot — soil types explained.
How the ground varies across Polk County
The USDA soil survey maps 32% of Polk County as poorly drained — but another 59% drains differently: 22% very poorly drained, 14% excessively drained.
Candler is the most extensive named soil at 10% of mapped acres, then Pomona (9%) and Smyrna (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 Polk County
Each reading below is measured for Polk 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 Polk 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 Polk County runs about pH 4.8–5.7, 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
MeasuredPolk County runs about 332 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
MeasuredPolk County sits in USDA hardiness zone 10a.
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 Polk County is in
Polk 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 Polk County
We scored all 1,086 plants against Polk County's own USDA zone 10a and its own 332-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 Polk 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 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 20 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
Documented around Polk County
- monarch butterfly228 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Polk County
USGS estimates 98,686 lb of 2,4-d on Polk County farmland in 2019, its largest by weight, ahead of Glyphosate (69,377 lb) and Chlorpyrifos (41,203 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 Polk County — and how to grow with it.
We checked the federal record across Polk County — 3,335 documented sites across 6 of the 9 source types we track.
The most significant on record: 30 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Polk County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Polk County
Closest first, across Polk County. Listing isn't leaking, and distance isn't exposure.
- ELOISE LOOP RD PROPERTYUnderground Storage Tanks · 0.8 mi
- WINTER HAVEN CITY - CHAIN OF LKS STADIUMUnderground Storage Tanks · 0.9 mi
- CITY OF WINTER HAVEN - WASTEWATER TREATMENT PLANT 3Brownfields · 0.9 mi
- WINTER HAVEN CITY-SEWER PLANT #3Underground Storage Tanks · 1.0 mi
- DIVISION OF FORESTRY-CYPRESS GARDENSUnderground Storage Tanks · 1.0 mi
- CSX INTERMODAL TERMINALS INCBrownfields · 1.1 mi
- ROUND LAKE ROLSW NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.2 mi
- ROUND LAKE ROUNW NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.3 mi
- ROUND LAKE ROLNW NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.3 mi
- ROUND LAKE ROLSE NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.4 mi
- ROUND LAKE ROUSE NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.4 mi
- ROUND LAKE ROLN NRSD WELL NEAR WINTER HAVEN FLNitrate · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Polk 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 Polk County.
Sources Checked
across Polk County
Severity Distribution
across Polk County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Polk 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 Polk County average
Your land is one point inside Polk County
Everything above resolves to Polk County as a whole — one PHZM band and one county frost record, read across 1.2M 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 Polk County Average
Polk County Average
- ●USDA Zones 10a, averaged across Polk County
- ●One soil character for all of Polk County
- ●Frost dates read at Polk County's scale: Jan 22 to Dec 20
YOUR Parcel
- ✓Your exact zone, not Polk County's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Polk County
Pull a site-specific report for your exact address in Polk County, Florida — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Polk County averages can't show:
We read public map data around Polk County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Polk County average
How we know this about Polk 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 Polk County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Polk County
When does frost risk typically end in Polk County?
The last hard freeze (28°F) in Polk County typically lands around Jan 22, 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 12.
How long is the growing season in Polk County?
Measured between 28°F hard freezes, Polk County sees about 332 frost-free days — roughly Jan 22 through Dec 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 12 to Dec 6, about 297 days.
Is the soil safe to grow vegetables in Polk County?
The federal record around Polk County runs heavier than most — 3,335 documented sites, mostly Underground Storage Tanks entries (1,692), the nearest Underground Storage Tanks record about 0.8 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Polk County's scale — its 10a band and its 332-day season. Your yard writes its own version of Polk 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 Polk County’s own scale
9 of the readings below were taken at Polk County's own scale — its own ~332-day span between 28°F freezes, the 3 most extensive soil series mapped here and 3,335 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Polk County's own USDA hardiness band, zones 10aUSDA PHZM 2023
- Polk County's own 28°F hard-freeze dates and its ~332-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Polk CountyUSDA NRCS SSURGO
- 3,335 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.8 miles outFederal environmental registers
- Polk County's boundary and the 1,151,017 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 10a and a ~332-day seasonGrowable Ground crop-matching engine
- Polk County sitting wholly inside the Southern Coastal PlainUS EPA Level III Ecoregions
- Open occurrence records documented in Polk County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Polk 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 Polk County — the ~332 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 Polk County's 1,151,017 acreswhy one lot differs from the next →
- Which of those 3,335 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 Polk Countyread your own land →