Caroline County, in Maryland, sits in USDA hardiness zone 7b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, prickly pear, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Caroline County lies within Delmarva Peninsula and Tidewater & Chesapeake — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Caroline County holds more than one microclimate.
Soils and elevations shift across Caroline 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 Caroline County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Caroline County — the short answer
Caroline County, Maryland: USDA zone 7b, about 233 days between hard freezes, across 204K acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 13
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~233
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 204K 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 Caroline County's average, not your lot's — a low corner or a tree line moves it. Against Caroline County's 233-day season, see what your own ground reads.
Heat in Caroline County
Across a year, Caroline County accumulates about 3,789 growing degree days above 50°F, about 75 fewer than the middle Maryland county — ahead of 10 of Maryland’s 24 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.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Caroline County
Across Caroline County, the ground is predominantly Ultisols, where Hambrook, Fallsington, and Ingleside are the most extensive named soil series. The soil is generally well drained with a sandy loam surface. Topsoil pH runs about 5.3–6.2, moderately acidic. Rainfall drains through hydrologic group B soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
56%
Hydric soils
30%
Soil still varies lot by lot — soil types explained.
How the ground varies across Caroline County
The USDA soil survey maps 46% of Caroline County as well drained — but another 53% drains differently: 23% poorly drained, 16% moderately well drained.
Hambrook is the most extensive named soil at 25% of mapped acres, then Fallsington (19%) and Ingleside (18%).
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 Caroline County
Each reading below is measured for Caroline 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 Caroline 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 Caroline County runs about pH 5.3–6.2, 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 30% of Caroline 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
MeasuredCaroline County runs about 233 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 Caroline County is in
Caroline County sits in the Middle Atlantic Coastal Plain — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Caroline County
We scored all 1,086 plants against Caroline County's own USDA zone 7b and its own 233-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 Maryland profile.
Is it too late to plant in Caroline County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 13 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Caroline County
Spotted lanternfly documented 4 miles from Caroline County, first recorded 2019. What to watch for.
- Japanese beetle4 documented records
- monarch butterfly109 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Caroline County
USGS estimates 197,366 lb of Glyphosate on Caroline County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (55,435 lb) and Atrazine (52,020 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 Caroline County — and how to grow with it.
We checked the federal record across Caroline County — 568 documented sites across 6 of the 9 source types we track.
The most significant on record: 5 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.
There's a meaningful federal record across Caroline 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 Caroline County
Closest first, across Caroline County. Listing isn't leaking, and distance isn't exposure.
- All Star Chev., Inc.Underground Storage Tanks · 1800 ft
- Denton ShellUnderground Storage Tanks · 1900 ft
- The Aqua CompanyUnderground Storage Tanks · 2000 ft
- CONNOLLY BROTHERS INCBrownfields · 2000 ft
- CO Dc 38Nitrate · 2000 ft
- CO Dd 84Nitrate · 2300 ft
- PETCO STORE #3802Brownfields · 2600 ft
- WALGREENS STORE #19451Brownfields · 2600 ft
- CO Dd 46Nitrate · 0.5 mi
- CO Dc 155Nitrate · 0.5 mi
- CO Dc 154Nitrate · 0.5 mi
- CO Dc 153Nitrate · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Caroline 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 Caroline County.
Total Sites
568
across Caroline County
Risk Level
Elevated
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
across Caroline County
Severity Distribution
across Caroline County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Caroline County, two things run higher than the national average across Caroline County — CAFO (121 sites) and Nitrate (234 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Caroline 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 Caroline County average
Your land is one point inside Caroline County
Everything above resolves to Caroline County as a whole — one PHZM band and one county frost record, read across 204K 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 Caroline County Average
Caroline County Average
- ●USDA Zones 7b, averaged across Caroline County
- ●One soil character for all of Caroline County
- ●Frost dates read at Caroline County's scale: Mar 25 to Nov 13
YOUR Parcel
- ✓Your exact zone, not Caroline County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Caroline County
Pull a site-specific report for your exact address in Caroline County, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Caroline County averages can't show:
We read public map data around Caroline County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Caroline County average
How we know this about Caroline 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 Caroline County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Caroline County
When does frost risk typically end in Caroline County?
The last hard freeze (28°F) in Caroline County typically lands around Mar 25, 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 15.
How long is the growing season in Caroline County?
Measured between 28°F hard freezes, Caroline County sees about 233 frost-free days — roughly Mar 25 through Nov 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Oct 30, about 198 days.
Is the soil safe to grow vegetables in Caroline County?
The federal record around Caroline County is a meaningful one — 568 documented sites, mostly Nitrate entries (234), the nearest Underground Storage Tanks record about 0.3 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 Caroline County's scale — its 7b band and its 233-day season. Your yard writes its own version of Caroline 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 Maryland's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Caroline County’s own scale
9 of the readings below were taken at Caroline County's own scale — its own ~233-day span between 28°F freezes, the 3 most extensive soil series mapped here and 568 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Caroline County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Caroline County's own 28°F hard-freeze dates and its ~233-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Caroline CountyUSDA NRCS SSURGO
- 568 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Caroline County's boundary and the 204,443 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~233-day seasonGrowable Ground crop-matching engine
- Caroline County sitting wholly inside the Middle Atlantic Coastal PlainUS EPA Level III Ecoregions
- Open occurrence records documented in Caroline County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Caroline County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Maryland grower plans around — written at state scale, so they stay on the state guidefrom Maryland
What this page can’t tell you
- How the season shifts across Caroline County — the ~233 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 Caroline County's 204,443 acreswhy one lot differs from the next →
- Which of those 568 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 Caroline Countyread your own land →