Jarrettsville, Maryland, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, hazelnut, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Jarrettsville, 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 Jarrettsville 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 Jarrettsville — soil, climate, flood, and parcel records. How we handle your address.
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Jarrettsville — the short answer
Jarrettsville, Maryland: USDA zone 7a, about 228 days between hard freezes, across 6K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~228
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 6K 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 7a is Jarrettsville's average, not your lot's — a low corner or a tree line moves it. Against Jarrettsville's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Jarrettsville
Each reading below is measured for Jarrettsville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJarrettsville runs about 228 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
MeasuredJarrettsville sits in USDA hardiness zone 7a.
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 Jarrettsville is in
Jarrettsville sits in the Northern Piedmont — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Jarrettsville's own centroid rather than borrowed from Harford County.
What Grows in Jarrettsville
Every plant below cleared Jarrettsville's own zone 7a and its 228-day season. Each card opens that plant's Maryland profile. How we score.
Is it too late to plant in Jarrettsville?
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 Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 12 — 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 Jarrettsville
Spotted lanternfly documented 3 miles from Jarrettsville, first recorded 2019. What to watch for.
What's on the federal record near Jarrettsville
Closest first, within ~10 miles of Jarrettsville. Listing isn't leaking, and distance isn't exposure.
- Kurtz Funeral Home, P.A.Underground Storage Tanks · 1700 ft
- Jarrettsville CO (GLC-27715)Underground Storage Tanks · 1900 ft
- Jarrettsville BPUnderground Storage Tanks · 1900 ft
- JACKS SMALL ENGINESBrownfields · 1900 ft
- SSC Jarrettsville L. P. Serv.Underground Storage Tanks · 2000 ft
- KEENE DODGE BODY SHOP INCBrownfields · 2000 ft
- HA Bb 107Nitrate · 2200 ft
- KEENE DODGEBrownfields · 2200 ft
- Edwin E. CalaryUnderground Storage Tanks · 2400 ft
- High's Dairy Store #86Underground Storage Tanks · 2400 ft
- Southern StatesUnderground Storage Tanks · 2400 ft
- Birchams Food MarketUnderground Storage Tanks · 2600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Jarrettsville'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 Jarrettsville.
Total Sites
764
within ~10 miles of Jarrettsville
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Jarrettsville
Severity Distribution
within ~10 miles of Jarrettsville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jarrettsville, Nitrate runs higher than the national average — 290 sites within ~10 miles of Jarrettsville. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Jarrettsville
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 Jarrettsville average
Your land is one point inside Jarrettsville
Everything above resolves to Jarrettsville as a whole — one PHZM band and one 28°F frost record, read across 6K 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 Jarrettsville Average
Jarrettsville Average
- ●USDA Zones 7a, averaged across Jarrettsville
- ●One soil character for all of Jarrettsville
- ●Frost dates read at Jarrettsville's scale: Mar 29 to Nov 12
YOUR Parcel
- ✓Your exact zone, not Jarrettsville's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Jarrettsville
Pull a site-specific report for your exact address in Jarrettsville, Maryland — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jarrettsville averages can't show:
We read public map data around Jarrettsville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jarrettsville average
How we know this about Jarrettsville
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 Jarrettsville’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 Jarrettsville
When does frost risk typically end in Jarrettsville?
The last hard freeze (28°F) in Jarrettsville typically lands around Mar 29, 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 19.
When is the first frost in Jarrettsville?
The first hard freeze (28°F) in Jarrettsville typically arrives around Nov 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 29, so the watching starts about Oct 13 — about 228 days after the spring freeze cleared.
How long is the growing season in Jarrettsville?
Measured between 28°F hard freezes, Jarrettsville sees about 228 frost-free days — roughly Mar 29 through Nov 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 29, about 193 days.
Is the soil safe to grow vegetables in Jarrettsville?
The federal record around Jarrettsville is a meaningful one — 764 documented sites, mostly Nitrate entries (290), the nearest Underground Storage Tanks record about 0.3 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 Jarrettsville?
From about Oct 13 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Jarrettsville's scale — its 7a band and its 228-day season. Your yard writes its own version of Jarrettsville'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 Jarrettsville’s own scale
7 of the readings below were taken at Jarrettsville's own scale — its own ~228-day season between 28°F freezes, the 5,526 acres it covers and 764 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Jarrettsville's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Jarrettsville's own 28°F hard-freeze dates, about Mar 29 and Nov 12 and the ~228-day span between themNOAA 1991–2020 Climate Normals
- 764 documented contamination sites on the federal record near Jarrettsville, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Jarrettsville's boundary and the 5,526 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~228-day seasonGrowable Ground crop-matching engine
- The ecoregion at Jarrettsville's own centroid, the Northern PiedmontUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Jarrettsvillelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Jarrettsville's 5,526 acres read through its county's SSURGO summaryfrom Harford County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Harford 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 Harford County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Jarrettsville's 5,526 acreswhy one lot differs from the next →
- Which side of Jarrettsville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,526 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.3 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 Jarrettsville-wide figureread your own land →
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