Sussex County, in Delaware, 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.
The conditions favor cabbage, prickly pear, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Sussex County lies within Delmarva Peninsula and Tidewater & Chesapeake — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Sussex County holds more than one microclimate.
Soils and elevations shift across Sussex County, so your frost dates and drainage aren't the county average. 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 Sussex County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Sussex County — the short answer
Sussex County, Delaware: USDA zone 7b, about 238 days between hard freezes, across 599K acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 23
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 16
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~238
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 599K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Sussex County's average, not your lot's — a low corner or a tree line moves it. Against Sussex County's 238-day season, see what your own ground reads.
Heat in Sussex County
Across a year, Sussex County accumulates about 3,762 growing degree days above 50°F, about 60 more than the middle Delaware county — ahead of every other Delaware county. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Sussex County
Across Sussex County, the ground is predominantly Ultisols, where Rosedale, Hurlock, and Pepperbox are the most extensive named soil series. The soil is generally well drained with a loamy sand surface. Topsoil pH runs about 5.5–6.2, moderately acidic. Rainfall drains through hydrologic group A soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
19%
Hydric soils
34%
Soil still varies lot by lot — soil types explained.
How the ground varies across Sussex County
The USDA soil survey maps 23% of Sussex County as well drained — but another 56% drains differently: 17% moderately well drained, 14% poorly drained.
Rosedale is the most extensive named soil at 11% of mapped acres, then Hurlock (9%) and Pepperbox (8%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Sussex County
Each reading below is measured for Sussex County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Sussex County are well drained, in hydrologic group A — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Sussex County runs about pH 5.5–6.2, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Wet ground
MeasuredAbout 34% of Sussex County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredSussex County runs about 238 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
The kind of country Sussex County is in
Sussex County sits in the Middle Atlantic Coastal Plain — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Sussex County
We scored all 1,086 plants against Sussex County's own USDA zone 7b and its own 238-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Delaware profile.
Is it too late to plant in Sussex County?
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 Feb 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 23 (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 Sussex County
Spotted lanternfly documented 3 miles from Sussex County, first recorded 2022. What to watch for.
- Japanese beetle57 documented records
- monarch butterfly234 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Sussex County
USGS estimates 407,619 lb of Glyphosate on Sussex County farmland in 2019, its largest by weight, ahead of Atrazine (297,426 lb) and Metolachlor & Metolachlor-s (207,031 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Sussex County — and how to grow with it.
We checked the federal record across Sussex County — 2,016 documented sites across 7 of the 9 source types we track.
The most significant on record: 20 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Sussex County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Sussex County
Closest first, across Sussex County. Listing isn't leaking, and distance isn't exposure.
- PATS AIRCRAFT, LLCBrownfields · 1.4 mi
- Edgehill Drugs IncUnderground Storage Tanks · 1.5 mi
- TAFQUnderground Storage Tanks · 1.5 mi
- DELMACO MANUFACTURING - 21424 CEDAR CREEK AVE, GEORGETOWNBrownfields · 1.6 mi
- JUSTIN TANKS, LLCToxics Release Inventory · 1.6 mi
- JUSTIN TANKS, LLCBrownfields · 1.6 mi
- D & B PRODUCTS / MULTI-TECH, INCToxics Release Inventory · 1.7 mi
- D & B PRODUCTS / MULTI-TECH, INCBrownfields · 1.7 mi
- Mfg Justin Tanks IncUnderground Storage Tanks · 1.7 mi
- IA Construction CorpUnderground Storage Tanks · 1.9 mi
- Three Bells MarketUnderground Storage Tanks · 2.1 mi
- Artcraft Lighting CenterUnderground Storage Tanks · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sussex County'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 Sussex County.
Severity Distribution
across Sussex County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sussex County, two things run higher than the national average across Sussex County — Nitrate (826 sites) and CAFO (21 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Sussex County
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 Sussex County average
Your land is one point inside Sussex County
Everything above resolves to Sussex County as a whole — one PHZM band and one county frost record, read across 599K 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 county 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 county average.
Your Lot vs the Sussex County Average
Sussex County Average
- ●USDA Zones 7b, averaged across Sussex County
- ●One soil character for all of Sussex County
- ●Frost dates read at Sussex County's scale: Mar 23 to Nov 16
YOUR Parcel
- ✓Your exact zone, not Sussex County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Sussex County
Pull a site-specific report for your exact address in Sussex County, Delaware — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sussex County averages can't show:
We read public map data around Sussex County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sussex County average
How we know this about Sussex County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Sussex County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Sussex County
When does frost risk typically end in Sussex County?
The last hard freeze (28°F) in Sussex County typically lands around Mar 23, 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 13.
How long is the growing season in Sussex County?
Measured between 28°F hard freezes, Sussex County sees about 238 frost-free days — roughly Mar 23 through Nov 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 13 to Nov 2, about 203 days.
Is the soil safe to grow vegetables in Sussex County?
The federal record around Sussex County runs heavier than most — 2,016 documented sites, mostly Underground Storage Tanks entries (867), the nearest Brownfields record about 1.4 miles 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.
Everything above is measured at Sussex County's scale — its 7b band and its 238-day season. Your yard writes its own version of Sussex County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Delaware's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Sussex County’s own scale
9 of the readings below were taken at Sussex County's own scale — its own ~238-day span between 28°F freezes, the 3 most extensive soil series mapped here and 2,016 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Sussex County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Sussex County's own 28°F hard-freeze dates and its ~238-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Sussex CountyUSDA NRCS SSURGO
- 2,016 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 1.4 miles outFederal environmental registers
- Sussex County's boundary and the 599,133 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~238-day seasonGrowable Ground crop-matching engine
- Sussex County sitting wholly inside the Middle Atlantic Coastal PlainUS EPA Level III Ecoregions
- Open occurrence records documented in Sussex County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Sussex County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Delaware grower plans around — written at state scale, so they stay on the state guidefrom Delaware
What this page can’t tell you
- How the season shifts across Sussex County — the ~238 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sussex County's 599,133 acreswhy one lot differs from the next →
- Which of those 2,016 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Sussex Countyread your own land →