Kemps Mill, Maryland, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cabbage, hazelnut, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Kemps Mill, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Kemps Mill lot. 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 Kemps Mill — soil, climate, flood, and parcel records. How we handle your address.
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Kemps Mill — the short answer
Kemps Mill, Maryland: USDA zone 7a, about 214 days between hard freezes, across 166 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~214
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 166 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 7a is Kemps Mill's average, not your lot's — a low corner or a tree line moves it. Against Kemps Mill's 214-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Kemps Mill
Each reading below is measured for Kemps Mill itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredKemps Mill runs about 214 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

Winter hardiness
MeasuredKemps Mill sits in USDA hardiness zone 7a.
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 Kemps Mill is in
Kemps Mill sits in the Ridge and Valley — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Kemps Mill's own centroid rather than borrowed from Washington County.
What Grows in Kemps Mill
Every plant below cleared Kemps Mill's own zone 7a and its 214-day season. Each card opens that plant's Maryland profile. How we score.






























Is it too late to plant in Kemps Mill?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Kemps Mill
Spotted lanternfly documented 3 miles from Kemps Mill, first recorded 2020. What to watch for.
What's on the federal record near Kemps Mill
Closest first, within ~10 miles of Kemps Mill. Listing isn't leaking, and distance isn't exposure.
- FEDEX FREIGHT HGRBrownfields · 1100 ft
- SHA BRIDGE #2107304Brownfields · 0.5 mi
- SHA BRIDGE 2114200Brownfields · 0.5 mi
- Old"" Keefer's Gulf StationUnderground Storage Tanks · 0.6 mi
- WALMART DISTRIBUTION CENTER #6046Brownfields · 0.6 mi
- Pilot Travel Center #150Underground Storage Tanks · 0.6 mi
- WASHINGTON COUNTY WATER QUALITYBrownfields · 0.7 mi
- QFN #506Underground Storage Tanks · 0.7 mi
- Warehouse & Terminal Properties LLCUnderground Storage Tanks · 0.7 mi
- XERXES CORPBrownfields · 0.8 mi
- XERXES CORPToxics Release Inventory · 0.8 mi
- RYDER HAGERSTOWN, MD LOC 0282Brownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kemps Mill'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 Kemps Mill.
Sources Checked
within ~10 miles of Kemps Mill
Severity Distribution
within ~10 miles of Kemps Mill
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 Kemps Mill
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 Kemps Mill average
Your land is one point inside Kemps Mill
Everything above resolves to Kemps Mill as a whole — one PHZM band and one 28°F frost record, read across 166 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 town 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 local average.
Your Lot vs the Kemps Mill Average
Kemps Mill Average
- ●USDA Zones 7a, averaged across Kemps Mill
- ●One soil character for all of Kemps Mill
- ●Frost dates read at Kemps Mill's scale: Apr 4 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Kemps Mill's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Kemps Mill
Pull a site-specific report for your exact address in Kemps Mill, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kemps Mill averages can't show:
We read public map data around Kemps Mill — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kemps Mill average
How we know this about Kemps Mill
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Kemps Mill’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Kemps Mill
When does frost risk typically end in Kemps Mill?
The last hard freeze (28°F) in Kemps Mill typically lands around Apr 4, 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 25.
When is the first frost in Kemps Mill?
The first hard freeze (28°F) in Kemps Mill typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 214 days after the spring freeze cleared.
How long is the growing season in Kemps Mill?
Measured between 28°F hard freezes, Kemps Mill sees about 214 frost-free days — roughly Apr 4 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 25 to Oct 21, about 179 days.
Is the soil safe to grow vegetables in Kemps Mill?
The federal record around Kemps Mill is a meaningful one — 948 documented sites, mostly Underground Storage Tanks entries (414), the nearest Brownfields record about 0.2 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.
How do I protect my plants from frost in Kemps Mill?
From about Oct 5 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 4 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Kemps Mill's scale — its 7a band and its 214-day season. Your yard writes its own version of Kemps Mill's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Kemps Mill’s own scale
7 of the readings below were taken at Kemps Mill's own scale — its own ~214-day season between 28°F freezes, the 166 acres it covers and 948 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Kemps Mill's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Kemps Mill's own 28°F hard-freeze dates, about Apr 4 and Nov 4 and the ~214-day span between themNOAA 1991–2020 Climate Normals
- 948 documented contamination sites on the federal record near Kemps Mill, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Kemps Mill's boundary and the 166 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~214-day seasonGrowable Ground crop-matching engine
- The ecoregion at Kemps Mill's own centroid, the Ridge and ValleyUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Kemps Milllydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Kemps Mill's 166 acres read through its county's SSURGO summaryfrom Washington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington County
- The growing challenges every Maryland grower plans around — written at state scale, so they stay on the state guidefrom Maryland
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Washington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Kemps Mill's 166 acreswhy one lot differs from the next →
- Which side of Kemps Mill you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 166 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Kemps Mill-wide figureread your own land →
