Martin 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.
Among the crops suited to this profile: okra, meyer lemon, california poppy, and artichoke. The site-level story — soil, sun, drainage — decides the rest.
Martin County lies within the Treasure Coast and the Everglades Agricultural Area — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Martin County holds more than one microclimate.
Soils and elevations shift across Martin 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 Martin County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Martin County — the short answer
Martin County, Florida: USDA zone 10a, about 330 days between hard freezes, across 348K acres.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 19
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Dec 15
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~330
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 348K 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 Martin County's average, not your lot's — a low corner or a tree line moves it. Against Martin County's 330-day season, see what your own ground reads.
Heat and winter chill in Martin County
Across a year, Martin County accumulates about 8,780 growing degree days above 50°F, about 1,395 more than the middle Florida county — ahead of 58 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 Martin County
Across Martin County, the ground is predominantly Spodosols, where Riviera, Wabasso, and Pineda are the most extensive named soil series. The soil is generally poorly drained with a fine sand surface. Topsoil pH runs about 5.3–6.1, moderately acidic. Rainfall drains through hydrologic group A/D soils.
Soil order
Spodosols
Drainage
Poorly drained
Hydric soils
44%
Soil still varies lot by lot — soil types explained.
How the ground varies across Martin County
The USDA soil survey maps 50% of Martin County as poorly drained — but another 29% drains differently: 21% very poorly drained, 3% excessively drained.
Riviera is the most extensive named soil at 17% of mapped acres, then Wabasso (11%) and Pineda (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 Martin County
Each reading below is measured for Martin 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 Martin 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 Martin County runs about pH 5.3–6.1, 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
MeasuredMartin County runs about 330 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
MeasuredMartin 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 Martin County is in
Martin County spans 2 EPA Level III ecoregions — Southern Coastal Plain (83%) and Southern Florida Coastal Plain (17%). 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 Martin County
We scored all 1,086 plants against Martin County's own USDA zone 10a and its own 330-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 Martin County?
Almost never — the real question is what to plant next. 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 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 15 — 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 Martin County
- monarch butterfly8 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Martin County
USGS estimates 45,373 lb of Glyphosate on Martin County farmland in 2019, its largest by weight, ahead of 2,4-d (12,808 lb) and Triclopyr (10,175 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 Martin County — and how to grow with it.
We checked the federal record across Martin County — 808 documented sites across 7 of the 9 source types we track.
The most significant on record: 4 Superfund sites. 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 Martin 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 Martin County
Closest first, across Martin County. Listing isn't leaking, and distance isn't exposure.
- M -1036Nitrate · 1.2 mi
- SOUTH FL WATER MGMT DIST-C-44 EAST STATUnderground Storage Tanks · 1.8 mi
- WELL AT OLYMPIA FLNitrate · 1.8 mi
- SOUTH FL WATER MGMT DIST-C-44 EXCHANGE PROPERTYUnderground Storage Tanks · 3.2 mi
- GARDINIER FL CITRUS-INDIANTOWN GROVEUnderground Storage Tanks · 3.3 mi
- CAULKINS CITRUS COUnderground Storage Tanks · 3.5 mi
- SORG 7Underground Storage Tanks · 3.5 mi
- PAYSON PARK THOROUGHBRED TRAINCAFO · 3.7 mi
- J & S FISH CAMPUnderground Storage Tanks · 4.2 mi
- STUART JET CENTER LLC-WESTUnderground Storage Tanks · 4.5 mi
- PERO GREENRIDGE FARMSUnderground Storage Tanks · 4.7 mi
- DEL MONTE FRESH PRODUCTION INCUnderground Storage Tanks · 4.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Martin 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 Martin County.
Severity Distribution
across Martin 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 Martin 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 Martin County average
Your land is one point inside Martin County
Everything above resolves to Martin County as a whole — one PHZM band and one county frost record, read across 348K 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 Martin County Average
Martin County Average
- ●USDA Zones 10a, averaged across Martin County
- ●One soil character for all of Martin County
- ●Frost dates read at Martin County's scale: Jan 19 to Dec 15
YOUR Parcel
- ✓Your exact zone, not Martin County's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Martin County
Pull a site-specific report for your exact address in Martin County, Florida — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Martin County averages can't show:
We read public map data around Martin County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Martin County average
How we know this about Martin 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 Martin County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Martin County
When does frost risk typically end in Martin County?
The last hard freeze (28°F) in Martin County typically lands around Jan 19, 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 9.
How long is the growing season in Martin County?
Measured between 28°F hard freezes, Martin County sees about 330 frost-free days — roughly Jan 19 through Dec 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 9 to Dec 1, about 295 days.
Is the soil safe to grow vegetables in Martin County?
The federal record around Martin County is a meaningful one — 808 documented sites, mostly Underground Storage Tanks entries (376), the nearest Nitrate record about 1.2 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 Martin County's scale — its 10a band and its 330-day season. Your yard writes its own version of Martin 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 Martin County’s own scale
9 of the readings below were taken at Martin County's own scale — its own ~330-day span between 28°F freezes, the 3 most extensive soil series mapped here and 808 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Martin County's own USDA hardiness band, zones 10aUSDA PHZM 2023
- Martin County's own 28°F hard-freeze dates and its ~330-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Martin CountyUSDA NRCS SSURGO
- 808 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Nitrate record about 1.2 miles outFederal environmental registers
- Martin County's boundary and the 348,079 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 10a and a ~330-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Martin County spans, Southern Coastal Plain the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Martin County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Martin 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 Martin County — the ~330 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 Martin County's 348,079 acreswhy one lot differs from the next →
- Which of those 808 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 Martin Countyread your own land →