Largo, Maryland, sits in USDA hardiness zone 7b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, prickly pear, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Largo, 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 Largo 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 Largo — soil, climate, flood, and parcel records. How we handle your address.
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Largo — the short answer
Largo, Maryland: USDA zone 7b, about 239 days between hard freezes, across 2K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~239
- 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 Largo's average, not your lot's — a low corner or a tree line moves it. Against Largo's 239-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Largo
Each reading below is measured for Largo itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLargo runs about 239 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
MeasuredLargo 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 Largo is in
Largo sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Largo's own centroid rather than borrowed from Prince George's County.
What Grows in Largo
Every plant below cleared Largo's own zone 7b and its 239-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Largo?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 22; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 16 — 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 Largo
Spotted lanternfly documented 3 miles from Largo, first recorded 2023. What to watch for.
What's on the federal record near Largo
Closest first, within ~10 miles of Largo. Listing isn't leaking, and distance isn't exposure.
- BEST CLEANERSBrownfields · 500 ft
- Global Montello Group Corp #1751Underground Storage Tanks · 0.7 mi
- LARGO HIGH SCHOOLBrownfields · 0.7 mi
- Prince George's Community CollegeUnderground Storage Tanks · 0.7 mi
- PRINCE GEORGE'S COMMUNITY COLLEGEBrownfields · 0.8 mi
- Kentland VFD Company 46Underground Storage Tanks · 0.8 mi
- Manor Care Health Services - LargoUnderground Storage Tanks · 0.9 mi
- LOWE'S OF LARGO, MD #702Brownfields · 0.9 mi
- HAMPTON ONE HOUR CLEANERSBrownfields · 0.9 mi
- USPS Southern MD PDCUnderground Storage Tanks · 0.9 mi
- Edgeworth Properties LLCUnderground Storage Tanks · 0.9 mi
- PENSKE TRUCK LEASING CO, LPBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Largo'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 Largo.
Sources Checked
within ~10 miles of Largo
Severity Distribution
within ~10 miles of Largo
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Largo, Superfund runs higher than the national average — 38 sites within ~10 miles of Largo. 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 Largo
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 Largo average
Your land is one point inside Largo
Everything above resolves to Largo 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 Largo Average
Largo Average
- ●USDA Zones 7b, averaged across Largo
- ●One soil character for all of Largo
- ●Frost dates read at Largo's scale: Mar 22 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Largo's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Largo
Pull a site-specific report for your exact address in Largo, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Largo averages can't show:
We read public map data around Largo — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Largo average
How we know this about Largo
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 Largo’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 Largo
When does frost risk typically end in Largo?
The last hard freeze (28°F) in Largo typically lands around Mar 22, 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 12.
When is the first frost in Largo?
The first hard freeze (28°F) in Largo typically arrives around Nov 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 2, so the watching starts about Oct 17 — about 239 days after the spring freeze cleared.
How long is the growing season in Largo?
Measured between 28°F hard freezes, Largo sees about 239 frost-free days — roughly Mar 22 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 12 to Nov 2, about 204 days.
Is the soil safe to grow vegetables in Largo?
The federal record around Largo is a meaningful one — 2,950 documented sites, mostly Underground Storage Tanks entries (1,654), the nearest Brownfields record under a tenth of a mile 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 Largo?
From about Oct 17 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Largo's scale — its 7b band and its 239-day season. Your yard writes its own version of Largo'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 Largo’s own scale
7 of the readings below were taken at Largo's own scale — its own ~239-day season between 28°F freezes, the 1,959 acres it covers and 2,950 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Largo's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Largo's own 28°F hard-freeze dates, about Mar 22 and Nov 16 and the ~239-day span between themNOAA 1991–2020 Climate Normals
- 2,950 documented contamination sites on the federal record near Largo, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Largo's boundary and the 1,959 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~239-day seasonGrowable Ground crop-matching engine
- The ecoregion at Largo's own centroid, the Southeastern PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Largolydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Largo's 1,959 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 Largo's 1,959 acreswhy one lot differs from the next →
- Which side of Largo you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,959 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Largo-wide figureread your own land →
More in Maryland
Wider growing context
What grows across MarylandLargo sits outside our named growing regions, so Maryland as a whole is its closest context here.
Nearby growing guides