Walker Mill, 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.
Crops well matched to these conditions include cabbage, prickly pear, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Walker 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 Walker 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 Walker Mill — soil, climate, flood, and parcel records. How we handle your address.
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Walker Mill — the short answer
Walker Mill, Maryland: USDA zone 7b, about 246 days between hard freezes, across 2K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~246
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 Walker Mill's average, not your lot's — a low corner or a tree line moves it. Against Walker Mill's 246-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Walker Mill
Each reading below is measured for Walker Mill itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWalker Mill runs about 246 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
MeasuredWalker Mill 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 Walker Mill is in
Walker Mill sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Walker Mill's own centroid rather than borrowed from Prince George's County.
What Grows in Walker Mill
Every plant below cleared Walker Mill's own zone 7b and its 246-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Walker Mill?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 20 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Walker Mill
Spotted lanternfly documented 4 miles from Walker Mill, first recorded 2021. What to watch for.
What's on the federal record near Walker Mill
Closest first, within ~10 miles of Walker Mill. Listing isn't leaking, and distance isn't exposure.
- Walker Mill Middle SchoolUnderground Storage Tanks · 650 ft
- WALKER MILL MIDDLE SCHOOLBrownfields · 700 ft
- POTOMAC ELECTRIC POWER COMPANY-RITCHIE SUBSTATION # 123Brownfields · 2500 ft
- CitgoUnderground Storage Tanks · 0.6 mi
- FAMILY DOLLAR #6590Brownfields · 0.7 mi
- Walker Mill BPUnderground Storage Tanks · 0.7 mi
- BP GAS STATIONBrownfields · 0.7 mi
- Spargo Enterprises Corp.Underground Storage Tanks · 0.7 mi
- NamcoUnderground Storage Tanks · 0.7 mi
- MARTINS CONSTRUCTIONBrownfields · 0.8 mi
- NU-LOOK 1 HR CLEANERSBrownfields · 0.9 mi
- METRO - 7308 CENTRAL AVENUE SITEBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Walker 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 Walker Mill.
Sources Checked
within ~10 miles of Walker Mill
Severity Distribution
within ~10 miles of Walker Mill
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Walker Mill, Superfund runs higher than the national average — 58 sites within ~10 miles of Walker Mill. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Walker 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 Walker Mill average
Your land is one point inside Walker Mill
Everything above resolves to Walker Mill as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Walker Mill Average
Walker Mill Average
- ●USDA Zones 7b, averaged across Walker Mill
- ●One soil character for all of Walker Mill
- ●Frost dates read at Walker Mill's scale: Mar 19 to Nov 20
YOUR Parcel
- ✓Your exact zone, not Walker Mill's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Walker Mill
Pull a site-specific report for your exact address in Walker Mill, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Walker Mill averages can't show:
We read public map data around Walker Mill — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Walker Mill average
How we know this about Walker 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 Walker 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 Walker Mill
When does frost risk typically end in Walker Mill?
The last hard freeze (28°F) in Walker Mill typically lands around Mar 19, 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 9.
When is the first frost in Walker Mill?
The first hard freeze (28°F) in Walker Mill typically arrives around Nov 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 6, so the watching starts about Oct 21 — about 246 days after the spring freeze cleared.
How long is the growing season in Walker Mill?
Measured between 28°F hard freezes, Walker Mill sees about 246 frost-free days — roughly Mar 19 through Nov 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 9 to Nov 6, about 211 days.
Is the soil safe to grow vegetables in Walker Mill?
The federal record around Walker Mill is a meaningful one — 4,429 documented sites, mostly Underground Storage Tanks entries (2,405), the nearest Underground Storage Tanks record about 0.1 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 Walker Mill?
From about Oct 21 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Walker Mill's scale — its 7b band and its 246-day season. Your yard writes its own version of Walker 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 Walker Mill’s own scale
7 of the readings below were taken at Walker Mill's own scale — its own ~246-day season between 28°F freezes, the 1,921 acres it covers and 4,429 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Walker Mill's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Walker Mill's own 28°F hard-freeze dates, about Mar 19 and Nov 20 and the ~246-day span between themNOAA 1991–2020 Climate Normals
- 4,429 documented contamination sites on the federal record near Walker Mill, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Walker Mill's boundary and the 1,921 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~246-day seasonGrowable Ground crop-matching engine
- The ecoregion at Walker Mill's own centroid, the Southeastern PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Walker Milllydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Walker Mill's 1,921 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 Walker Mill's 1,921 acreswhy one lot differs from the next →
- Which side of Walker 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 1,921 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Walker Mill-wide figureread your own land →
More in Maryland
Wider growing context
What grows across MarylandWalker Mill sits outside our named growing regions, so Maryland as a whole is its closest context here.
Nearby growing guides