Delaware, New Jersey, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
The conditions favor cabbage, pawpaw, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Delaware, 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 Delaware 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 Delaware — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Delaware — the short answer
Delaware, New Jersey: USDA zone 7a, about 207 days between hard freezes, across 332 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~207
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 332 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 Delaware's average, not your lot's — a low corner or a tree line moves it. Against Delaware's 207-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Delaware
Each reading below is measured for Delaware itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDelaware runs about 207 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
MeasuredDelaware 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 Delaware is in
Delaware sits in the Ridge and Valley — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Delaware's own centroid rather than borrowed from Warren County.
What Grows in Delaware
Every plant below cleared Delaware's own zone 7a and its 207-day season. Each card opens that plant's New Jersey profile. How we score.
Is it too late to plant in Delaware?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 31 — 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 Delaware
Spotted lanternfly documented 1 miles from Delaware, first recorded 2019. What to watch for.
What's on the federal record near Delaware
Closest first, within ~10 miles of Delaware. Listing isn't leaking, and distance isn't exposure.
- 23 ROUTE 46Underground Storage Tanks · 1000 ft
- COLUMBIA MAINT YARDUnderground Storage Tanks · 1000 ft
- KNOWLTON TWP BD OF EDUnderground Storage Tanks · 1000 ft
- C&D VAN HORN INCUnderground Storage Tanks · 1200 ft
- DENNIS ACI INCUnderground Storage Tanks · 1700 ft
- GARY W GRAY TRUCKING INCUnderground Storage Tanks · 1700 ft
- KNOWLTON TWP ELEMENTARY SCHOOL DISTRICTUnderground Storage Tanks · 1800 ft
- BPUnderground Storage Tanks · 2000 ft
- CUSTOM LAMINATING CORPToxics Release Inventory · 1.2 mi
- PORTLAND GENERATING STAUnderground Storage Tanks · 1.4 mi
- NP 169Nitrate · 1.5 mi
- PORTLAND COMBUSTION TURBINEToxics Release Inventory · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Delaware'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 Delaware.
Sources Checked
within ~10 miles of Delaware
Severity Distribution
within ~10 miles of Delaware
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Delaware
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 Delaware average
Your land is one point inside Delaware
Everything above resolves to Delaware as a whole — one PHZM band and one 28°F frost record, read across 332 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 Delaware Average
Delaware Average
- ●USDA Zones 7a, averaged across Delaware
- ●One soil character for all of Delaware
- ●Frost dates read at Delaware's scale: Apr 7 to Oct 31
YOUR Parcel
- ✓Your exact zone, not Delaware's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Delaware
Pull a site-specific report for your exact address in Delaware, New Jersey — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Delaware averages can't show:
We read public map data around Delaware — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Delaware average
How we know this about Delaware
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 Delaware’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 Delaware
When does frost risk typically end in Delaware?
The last hard freeze (28°F) in Delaware typically lands around Apr 7, 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 28.
When is the first frost in Delaware?
The first hard freeze (28°F) in Delaware typically arrives around Oct 31, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 17, so the watching starts about Oct 1 — about 207 days after the spring freeze cleared.
How long is the growing season in Delaware?
Measured between 28°F hard freezes, Delaware sees about 207 frost-free days — roughly Apr 7 through Oct 31, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 28 to Oct 17, about 172 days.
Is the soil safe to grow vegetables in Delaware?
The federal record around Delaware is a meaningful one — 554 documented sites, mostly Underground Storage Tanks entries (339), the nearest Underground Storage Tanks record about 0.2 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 Delaware?
From about Oct 1 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 Oct 31 (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 Oct 31. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Delaware's scale — its 7a band and its 207-day season. Your yard writes its own version of Delaware'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 Delaware’s own scale
7 of the readings below were taken at Delaware's own scale — its own ~207-day season between 28°F freezes, the 332 acres it covers and 554 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Delaware's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Delaware's own 28°F hard-freeze dates, about Apr 7 and Oct 31 and the ~207-day span between themNOAA 1991–2020 Climate Normals
- 554 documented contamination sites on the federal record near Delaware, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Delaware's boundary and the 332 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~207-day seasonGrowable Ground crop-matching engine
- The ecoregion at Delaware's own centroid, the Ridge and ValleyUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Delawarelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Delaware's 332 acres read through its county's SSURGO summaryfrom Warren County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Warren County
- The growing challenges every New Jersey grower plans around — written at state scale, so they stay on the state guidefrom New Jersey
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Warren County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Delaware's 332 acreswhy one lot differs from the next →
- Which side of Delaware you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 332 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Delaware-wide figureread your own land →