Mount Briar, Maryland, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
On paper, cabbage, hazelnut, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Mount Briar, 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 Mount Briar 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 Mount Briar — soil, climate, flood, and parcel records. How we handle your address.
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Mount Briar — the short answer
Mount Briar, Maryland: USDA zone 7a, about 213 days between hard freezes, across 399 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- 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
- ~213
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 399 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 Mount Briar's average, not your lot's — a low corner or a tree line moves it. Against Mount Briar's 213-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mount Briar
Each reading below is measured for Mount Briar itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMount Briar runs about 213 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
MeasuredMount Briar 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 Mount Briar is in
Mount Briar sits in the Blue Ridge — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Mount Briar's own centroid, and it is not what its county reads: Washington County is mostly Ridge and Valley. The wider page above you is answering a different question about different ground.
What Grows in Mount Briar
Every plant below cleared Mount Briar's own zone 7a and its 213-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Mount Briar?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (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. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Mount Briar
Spotted lanternfly documented 2 miles from Mount Briar, first recorded 2019. What to watch for.
What's on the federal record near Mount Briar
Closest first, within ~10 miles of Mount Briar. Listing isn't leaking, and distance isn't exposure.
- WA Di 5Nitrate · 0.6 mi
- Old Keedysville Train StationUnderground Storage Tanks · 0.9 mi
- Millbrook MarketUnderground Storage Tanks · 1.0 mi
- BOONSBORO - KEEDYSVILLEPFAS · 1.2 mi
- WA Di 10Nitrate · 2.4 mi
- WA Di 199Nitrate · 2.5 mi
- K & M GroceryUnderground Storage Tanks · 2.5 mi
- Antietam Wastewater Treatment PlantUnderground Storage Tanks · 3.1 mi
- Washington County Roads-Southern SectionUnderground Storage Tanks · 3.1 mi
- James Giffin PropertyUnderground Storage Tanks · 3.1 mi
- WA Di 1Nitrate · 3.1 mi
- Antietam National Battlefield Maintenance FacilityUnderground Storage Tanks · 3.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mount Briar'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 Mount Briar.
Total Sites
641
within ~10 miles of Mount Briar
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Mount Briar
Severity Distribution
within ~10 miles of Mount Briar
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mount Briar, Nitrate runs higher than the national average — 422 sites within ~10 miles of Mount Briar. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Mount Briar
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 Mount Briar average
Your land is one point inside Mount Briar
Everything above resolves to Mount Briar as a whole — one PHZM band and one 28°F frost record, read across 399 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 Mount Briar Average
Mount Briar Average
- ●USDA Zones 7a, averaged across Mount Briar
- ●One soil character for all of Mount Briar
- ●Frost dates read at Mount Briar's scale: Apr 5 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Mount Briar's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mount Briar
Pull a site-specific report for your exact address in Mount Briar, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mount Briar averages can't show:
We read public map data around Mount Briar — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mount Briar average
How we know this about Mount Briar
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 Mount Briar’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 Mount Briar
When does frost risk typically end in Mount Briar?
The last hard freeze (28°F) in Mount Briar typically lands around Apr 5, 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 26.
When is the first frost in Mount Briar?
The first hard freeze (28°F) in Mount Briar 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 213 days after the spring freeze cleared.
How long is the growing season in Mount Briar?
Measured between 28°F hard freezes, Mount Briar sees about 213 frost-free days — roughly Apr 5 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 21, about 178 days.
Is the soil safe to grow vegetables in Mount Briar?
The federal record around Mount Briar is a meaningful one — 641 documented sites, mostly Nitrate entries (422), the nearest Nitrate record about 0.6 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 Mount Briar?
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 Mount Briar's scale — its 7a band and its 213-day season. Your yard writes its own version of Mount Briar'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 Mount Briar’s own scale
7 of the readings below were taken at Mount Briar's own scale — its own ~213-day season between 28°F freezes, the 399 acres it covers and 641 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mount Briar's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Mount Briar's own 28°F hard-freeze dates, about Apr 5 and Nov 4 and the ~213-day span between themNOAA 1991–2020 Climate Normals
- 641 documented contamination sites on the federal record near Mount Briar, the closest Nitrate record about 0.6 miles out from the town centreFederal environmental registers
- Mount Briar's boundary and the 399 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~213-day seasonGrowable Ground crop-matching engine
- Mount Briar sits in the Blue Ridge — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Mount Briarlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Mount Briar's 399 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 Mount Briar's 399 acreswhy one lot differs from the next →
- Which side of Mount Briar you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 399 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.6 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 Mount Briar-wide figureread your own land →