Severn, Maryland, sits in USDA hardiness zone 7b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with cabbage, prickly pear, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Severn, 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 Severn 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 Severn — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Severn — the short answer
Severn, Maryland: USDA zone 7b, about 231 days between hard freezes, across 12K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~231
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 12K 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 Severn's average, not your lot's — a low corner or a tree line moves it. Against Severn's 231-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Severn
Each reading below is measured for Severn itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSevern runs about 231 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
MeasuredSevern 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 Severn is in
Severn sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Severn's own centroid rather than borrowed from Anne Arundel County.
What Grows in Severn
Every plant below cleared Severn's own zone 7b and its 231-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Severn?
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 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 11 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Severn
Spotted lanternfly documented 3 miles from Severn, first recorded 2021. What to watch for.
What's on the federal record near Severn
Closest first, within ~10 miles of Severn. Listing isn't leaking, and distance isn't exposure.
- Severn TransmissionUnderground Storage Tanks · 500 ft
- 28353 Shahzad, Inc.Underground Storage Tanks · 2500 ft
- CVS PHARMACY #2883Brownfields · 0.5 mi
- Royal Farms #040Underground Storage Tanks · 0.6 mi
- CAVALIER CLEANERSBrownfields · 0.6 mi
- ADVANCE AUTO PARTS #7746Brownfields · 0.6 mi
- Telegraph LiquorsUnderground Storage Tanks · 0.8 mi
- Edwin D. Bell & Sons, Inc.Underground Storage Tanks · 0.9 mi
- Mack Trucks, Inc.Underground Storage Tanks · 0.9 mi
- K & K Trash Removal Inc.Underground Storage Tanks · 0.9 mi
- SSC CorporationUnderground Storage Tanks · 0.9 mi
- PENSKE TRUCK LEASING CO., LPBrownfields · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Severn'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 Severn.
Sources Checked
within ~10 miles of Severn
Severity Distribution
within ~10 miles of Severn
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 Severn
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 Severn average
Your land is one point inside Severn
Everything above resolves to Severn as a whole — one PHZM band and one 28°F frost record, read across 12K 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 Severn Average
Severn Average
- ●USDA Zones 7b, averaged across Severn
- ●One soil character for all of Severn
- ●Frost dates read at Severn's scale: Mar 25 to Nov 11
YOUR Parcel
- ✓Your exact zone, not Severn's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Severn
Pull a site-specific report for your exact address in Severn, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Severn averages can't show:
We read public map data around Severn — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Severn average
How we know this about Severn
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 Severn’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 Severn
When does frost risk typically end in Severn?
The last hard freeze (28°F) in Severn typically lands around Mar 25, 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 15.
When is the first frost in Severn?
The first hard freeze (28°F) in Severn typically arrives around Nov 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 28, so the watching starts about Oct 12 — about 231 days after the spring freeze cleared.
How long is the growing season in Severn?
Measured between 28°F hard freezes, Severn sees about 231 frost-free days — roughly Mar 25 through Nov 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 15 to Oct 28, about 196 days.
Is the soil safe to grow vegetables in Severn?
The federal record around Severn runs heavier than most — 3,028 documented sites, mostly Underground Storage Tanks entries (1,302), the nearest Underground Storage Tanks record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Severn?
From about Oct 12 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Severn's scale — its 7b band and its 231-day season. Your yard writes its own version of Severn'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 Severn’s own scale
7 of the readings below were taken at Severn's own scale — its own ~231-day season between 28°F freezes, the 11,737 acres it covers and 3,028 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Severn's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Severn's own 28°F hard-freeze dates, about Mar 25 and Nov 11 and the ~231-day span between themNOAA 1991–2020 Climate Normals
- 3,028 documented contamination sites on the federal record near Severn, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Severn's boundary and the 11,737 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~231-day seasonGrowable Ground crop-matching engine
- The ecoregion at Severn's own centroid, the Southeastern PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Severnlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Severn's 11,737 acres read through its county's SSURGO summaryfrom Anne Arundel County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Anne Arundel 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 Anne Arundel County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Severn's 11,737 acreswhy one lot differs from the next →
- Which side of Severn you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 11,737 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Severn-wide figureread your own land →
More in Maryland
Wider growing context
What grows across MarylandSevern sits outside our named growing regions, so Maryland as a whole is its closest context here.
Nearby growing guides