What Grows in Caroline County, Maryland

Caroline County sits in USDA hardiness zone 7b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 9 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 7 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

The last hard freeze (28°F) in Caroline County typically lands around Mar 9, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

Measured between 28°F hard freezes, Caroline County sees about 273 frost-free days — roughly Mar 9 through Dec 7, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.

Caroline County's zone 7b supports a wide range — strong performers include Tomato, Black-eyed Susan, Peach, Sweet Corn, and Crab Apple. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Officially, Caroline County sits in USDA zone 7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

The federal record around Caroline County is a meaningful one — 568 documented sites — 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.

Start with three facts. Caroline County sits in USDA zone 7b, which sets what survives winter; the last 28°F hard freeze typically clears around Mar 9, with about 273 frost-free days to work with (NOAA 1991–2020 climate normals); and 568 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.