Dover, Delaware, sits in USDA hardiness zone 7b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, prickly pear, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Dover, 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 Dover 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 Dover — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Dover — the short answer
Dover, Delaware: USDA zone 7b, about 237 days between hard freezes, across 15K acres of city.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 24
- 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
- ~237
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 15K 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 Dover's average, not your lot's — a low corner or a tree line moves it. Against Dover's 237-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Dover
Each reading below is measured for Dover itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDover runs about 237 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
MeasuredDover 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 Dover is in
Dover sits in the Middle Atlantic Coastal Plain — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Dover's own centroid rather than borrowed from Kent County.
What Grows in Dover
Every plant below cleared Dover's own zone 7b and its 237-day season. Each card opens that plant's Delaware profile. How we score.
Is it too late to plant in Dover?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 24 (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. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Dover
Spotted lanternfly documented 2 miles from Dover, first recorded 2020. What to watch for.
What's on the federal record near Dover
Closest first, within ~10 miles of Dover. Listing isn't leaking, and distance isn't exposure.
- Andrews MarketUnderground Storage Tanks · 450 ft
- Moores Lake Fish PondUnderground Storage Tanks · 450 ft
- Roses Blue Hen Mall Dept StoreUnderground Storage Tanks · 450 ft
- DSWA Delaware Solid Waste AuthorityUnderground Storage Tanks · 450 ft
- Delaware Air ParkUnderground Storage Tanks · 450 ft
- Reichhold Chemicals IncUnderground Storage Tanks · 450 ft
- DNREC Dept of Natural ResourcesUnderground Storage Tanks · 700 ft
- DNREC-ENVIRONMENTAL SERVICESBrownfields · 700 ft
- Bell Atlantic 95020 DoverUnderground Storage Tanks · 1000 ft
- B/R Corp Muriel SchwartzUnderground Storage Tanks · 1300 ft
- Legislative HallUnderground Storage Tanks · 1300 ft
- DANG John Haslet ArmoryUnderground Storage Tanks · 1500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Dover'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 Dover.
Sources Checked
within ~10 miles of Dover
Severity Distribution
within ~10 miles of Dover
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Dover, PFAS runs higher than the national average — 7 sites within ~10 miles of Dover. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Dover
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 Dover average
Your land is one point inside Dover
Everything above resolves to Dover as a whole — one PHZM band and one 28°F frost record, read across 15K 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 city 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 Dover Average
Dover Average
- ●USDA Zones 7b, averaged across Dover
- ●One soil character for all of Dover
- ●Frost dates read at Dover's scale: Mar 24 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Dover's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Dover
Pull a site-specific report for your exact address in Dover, Delaware — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Dover averages can't show:
We read public map data around Dover — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Dover average
How we know this about Dover
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Dover’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 city grain anywhere on this page — there is no city-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 Dover
When does frost risk typically end in Dover?
The last hard freeze (28°F) in Dover typically lands around Mar 24, 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 14.
When is the first frost in Dover?
The first hard freeze (28°F) in Dover 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 237 days after the spring freeze cleared.
How long is the growing season in Dover?
Measured between 28°F hard freezes, Dover sees about 237 frost-free days — roughly Mar 24 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 14 to Nov 2, about 202 days.
Is the soil safe to grow vegetables in Dover?
The federal record around Dover runs heavier than most — 659 documented sites, mostly Underground Storage Tanks entries (371), 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 Dover?
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 Dover's scale — its 7b band and its 237-day season. Your yard writes its own version of Dover'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 Dover’s own scale
7 of the readings below were taken at Dover's own scale — its own ~237-day season between 28°F freezes, the 15,243 acres it covers and 659 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Dover's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Dover's own 28°F hard-freeze dates, about Mar 24 and Nov 16 and the ~237-day span between themNOAA 1991–2020 Climate Normals
- 659 documented contamination sites on the federal record near Dover, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Dover's boundary and the 15,243 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~237-day seasonGrowable Ground crop-matching engine
- The ecoregion at Dover's own centroid, the Middle Atlantic Coastal PlainUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Doverlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Dover's 15,243 acres read through its county's SSURGO summaryfrom Kent County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kent County
- The growing challenges every Delaware grower plans around — written at state scale, so they stay on the state guidefrom Delaware
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Kent County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Dover's 15,243 acreswhy one lot differs from the next →
- Which side of Dover you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 15,243 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 Dover-wide figureread your own land →