Glassmanor, 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.
The conditions favor cabbage, prickly pear, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Glassmanor, 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 Glassmanor 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 Glassmanor — soil, climate, flood, and parcel records. How we handle your address.
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Glassmanor — the short answer
Glassmanor, Maryland: USDA zone 7b, about 261 days between hard freezes, across 1K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~261
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 7b is Glassmanor's average, not your lot's — a low corner or a tree line moves it. Against Glassmanor's 261-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Glassmanor
Each reading below is measured for Glassmanor itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGlassmanor runs about 261 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
MeasuredGlassmanor sits in USDA hardiness zone 7b.
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 Glassmanor is in
Glassmanor sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Glassmanor's own centroid rather than borrowed from Prince George's County.
What Grows in Glassmanor
Every plant below cleared Glassmanor's own zone 7b and its 261-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Glassmanor?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 29 — 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.
Documented around Glassmanor
Spotted lanternfly documented 2 miles from Glassmanor, first recorded 2023. What to watch for.
What's on the federal record near Glassmanor
Closest first, within ~10 miles of Glassmanor. Listing isn't leaking, and distance isn't exposure.
- POTOMAC HSBrownfields · 2200 ft
- Constellation Centre OneUnderground Storage Tanks · 0.5 mi
- STAR CLEANERSBrownfields · 0.7 mi
- Forest KnollsUnderground Storage Tanks · 0.8 mi
- Amoco Oil CompanyUnderground Storage Tanks · 0.8 mi
- Livingston Road BPUnderground Storage Tanks · 0.8 mi
- NORRIS GARAGEBrownfields · 0.8 mi
- WSSC - ST BARNABAS ELEVATED TANKBrownfields · 0.8 mi
- GOODYEAR AUTO SERVICE CTR - OXON HILLBrownfields · 0.8 mi
- Xotic Motor SportsUnderground Storage Tanks · 0.8 mi
- Town of Forest Heights, Inc.Underground Storage Tanks · 0.8 mi
- SS #25728Underground Storage Tanks · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Glassmanor'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 Glassmanor.
Sources Checked
within ~10 miles of Glassmanor
Severity Distribution
within ~10 miles of Glassmanor
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Glassmanor, Superfund runs higher than the national average — 61 sites within ~10 miles of Glassmanor. That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Glassmanor
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 Glassmanor average
Your land is one point inside Glassmanor
Everything above resolves to Glassmanor as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Glassmanor Average
Glassmanor Average
- ●USDA Zones 7b, averaged across Glassmanor
- ●One soil character for all of Glassmanor
- ●Frost dates read at Glassmanor's scale: Mar 13 to Nov 29
YOUR Parcel
- ✓Your exact zone, not Glassmanor's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Glassmanor
Pull a site-specific report for your exact address in Glassmanor, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Glassmanor averages can't show:
We read public map data around Glassmanor — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Glassmanor average
How we know this about Glassmanor
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 Glassmanor’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 Glassmanor
When does frost risk typically end in Glassmanor?
The last hard freeze (28°F) in Glassmanor typically lands around Mar 13, 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 3.
When is the first frost in Glassmanor?
The first hard freeze (28°F) in Glassmanor typically arrives around Nov 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 15, so the watching starts about Oct 30 — about 261 days after the spring freeze cleared.
How long is the growing season in Glassmanor?
Measured between 28°F hard freezes, Glassmanor sees about 261 frost-free days — roughly Mar 13 through Nov 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 3 to Nov 15, about 226 days.
Is the soil safe to grow vegetables in Glassmanor?
The federal record around Glassmanor is a meaningful one — 4,928 documented sites, mostly Underground Storage Tanks entries (2,720), the nearest Brownfields record about 0.4 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 Glassmanor?
From about Oct 30 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 29 (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 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Glassmanor's scale — its 7b band and its 261-day season. Your yard writes its own version of Glassmanor'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 Glassmanor’s own scale
7 of the readings below were taken at Glassmanor's own scale — its own ~261-day season between 28°F freezes, the 1,479 acres it covers and 4,928 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Glassmanor's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Glassmanor's own 28°F hard-freeze dates, about Mar 13 and Nov 29 and the ~261-day span between themNOAA 1991–2020 Climate Normals
- 4,928 documented contamination sites on the federal record near Glassmanor, the closest Brownfields record about 0.4 miles out from the town centreFederal environmental registers
- Glassmanor's boundary and the 1,479 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~261-day seasonGrowable Ground crop-matching engine
- The ecoregion at Glassmanor's own centroid, the Southeastern PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Glassmanorlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Glassmanor's 1,479 acres read through its county's SSURGO summaryfrom Prince George's County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Prince George's 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 Prince George's County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Glassmanor's 1,479 acreswhy one lot differs from the next →
- Which side of Glassmanor you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,479 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.4 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 Glassmanor-wide figureread your own land →
More in Maryland
Wider growing context
What grows across MarylandGlassmanor sits outside our named growing regions, so Maryland as a whole is its closest context here.
Nearby growing guides