Herald Harbor, 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.
Well-matched crops include cabbage, prickly pear, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Herald Harbor, 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 Herald Harbor 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 Herald Harbor — soil, climate, flood, and parcel records. How we handle your address.
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Herald Harbor — the short answer
Herald Harbor, Maryland: USDA zone 7b, about 246 days between hard freezes, across 1K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~246
- 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 Herald Harbor's average, not your lot's — a low corner or a tree line moves it. Against Herald Harbor's 246-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Herald Harbor
Each reading below is measured for Herald Harbor itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredHerald Harbor 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
MeasuredHerald Harbor 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 Herald Harbor is in
Herald Harbor sits in the Southeastern Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Herald Harbor's own centroid rather than borrowed from Anne Arundel County.
What Grows in Herald Harbor
Every plant below cleared Herald Harbor'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 Herald Harbor?
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 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 21 — 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 Herald Harbor
Spotted lanternfly documented 3 miles from Herald Harbor, first recorded 2020. What to watch for.
What's on the federal record near Herald Harbor
Closest first, within ~10 miles of Herald Harbor. Listing isn't leaking, and distance isn't exposure.
- Herald Harbor Volunteer Fire DepartmentUnderground Storage Tanks · 600 ft
- AA Ce 116Nitrate · 1900 ft
- Smith's Marina Inc.Underground Storage Tanks · 0.6 mi
- AA Ce 32Nitrate · 0.8 mi
- AA Ce 4Nitrate · 0.8 mi
- AA Ce 33Nitrate · 0.9 mi
- AA Ce 38Nitrate · 1.0 mi
- Boones Trail Pumping StationUnderground Storage Tanks · 1.2 mi
- AA Ce 36Nitrate · 1.2 mi
- Crownsville Veterans CemeteryUnderground Storage Tanks · 1.3 mi
- Ashberry Pumping StationUnderground Storage Tanks · 1.4 mi
- Colchester Pumping StationUnderground Storage Tanks · 1.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Herald Harbor'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 Herald Harbor.
Total Sites
1,765
within ~10 miles of Herald Harbor
Risk Level
Elevated
Highest-severity
13 Superfund sites
Sources Checked
within ~10 miles of Herald Harbor
Severity Distribution
within ~10 miles of Herald Harbor
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 Herald Harbor
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 Herald Harbor average
Your land is one point inside Herald Harbor
Everything above resolves to Herald Harbor 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 Herald Harbor Average
Herald Harbor Average
- ●USDA Zones 7b, averaged across Herald Harbor
- ●One soil character for all of Herald Harbor
- ●Frost dates read at Herald Harbor's scale: Mar 20 to Nov 21
YOUR Parcel
- ✓Your exact zone, not Herald Harbor's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Herald Harbor
Pull a site-specific report for your exact address in Herald Harbor, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Herald Harbor averages can't show:
We read public map data around Herald Harbor — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Herald Harbor average
How we know this about Herald Harbor
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 Herald Harbor’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 Herald Harbor
When does frost risk typically end in Herald Harbor?
The last hard freeze (28°F) in Herald Harbor typically lands around Mar 20, 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 10.
When is the first frost in Herald Harbor?
The first hard freeze (28°F) in Herald Harbor typically arrives around Nov 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 7, so the watching starts about Oct 22 — about 246 days after the spring freeze cleared.
How long is the growing season in Herald Harbor?
Measured between 28°F hard freezes, Herald Harbor sees about 246 frost-free days — roughly Mar 20 through Nov 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 10 to Nov 7, about 211 days.
Is the soil safe to grow vegetables in Herald Harbor?
The federal record around Herald Harbor is a meaningful one — 1,765 documented sites, mostly Underground Storage Tanks entries (845), 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 Herald Harbor?
From about Oct 22 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 21 (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 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Herald Harbor's scale — its 7b band and its 246-day season. Your yard writes its own version of Herald Harbor'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 Herald Harbor’s own scale
7 of the readings below were taken at Herald Harbor's own scale — its own ~246-day season between 28°F freezes, the 1,075 acres it covers and 1,765 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Herald Harbor's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Herald Harbor's own 28°F hard-freeze dates, about Mar 20 and Nov 21 and the ~246-day span between themNOAA 1991–2020 Climate Normals
- 1,765 documented contamination sites on the federal record near Herald Harbor, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Herald Harbor's boundary and the 1,075 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 Herald Harbor's own centroid, the Southeastern PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Herald Harborlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Herald Harbor's 1,075 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 Herald Harbor's 1,075 acreswhy one lot differs from the next →
- Which side of Herald Harbor you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,075 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 Herald Harbor-wide figureread your own land →
More in Maryland
Wider growing context
What grows across MarylandHerald Harbor sits outside our named growing regions, so Maryland as a whole is its closest context here.
Nearby growing guides
