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 tomato, sweet corn, peach, and blueberry, 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 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
7b
Last Hard Freeze (28°F)
Mar 4
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Dec 15
County normal — light frosts arrive a few weeks earlier
County Area
599K acres
Hardiness Zone Range
Zone maps are averages across Sussex County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
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.
What Grows in Sussex County
Plants matched to Sussex County's USDA zones 7b — each links to its full growing 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 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 15 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
Growing Challenges in Delaware
What an experienced grower plans around here — each one has a move.
Sandy soils in southern DE drain too quickly
Organic matter is the fix, applied annually — compost and cover crops teach sandy ground to hold water and nutrients.
Salt spray damage near the coast
Salt-tolerant species up front and a windbreak line behind — a layered coastal defense that catches the spray.
Rising water tables in low-lying areas
Where the water table rises, grow up: mounded rows and raised beds keep roots out of saturated ground.
For cultivar selection, pest pressure, and planting-time guidance specific to Delaware, the University of Delaware Cooperative Extension is the authoritative local source.
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.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
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 — 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 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Sussex County Average
- ●USDA Zones 7b
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓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 exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Sussex County, Delaware
- USDA Hardiness Zones: 7b (USDA PHZM 2023)
- Last Hard Freeze (28°F): Mar 4 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Dec 15 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~286 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 599K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Sussex County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Sussex County, Delaware?
Sussex County sits in USDA hardiness zone 7b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
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 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 15 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
When does frost risk typically end in Sussex County?
The last hard freeze (28°F) in Sussex County typically lands around Mar 4, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Sussex County?
Measured between 28°F hard freezes, Sussex County sees about 286 frost-free days — roughly Mar 4 through Dec 15, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Sussex County?
Sussex County's zone 7b supports a wide range — strong performers include Tomato, Sweet Corn, Peach, Blueberry, and Holly. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Sussex County, really?
Officially, Sussex County sits in USDA zone 7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Sussex County?
The federal record around Sussex County runs heavier than most — 2,016 documented sites — 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.
Just moved to Sussex County — what should I know before planting?
Start with three facts. Sussex County sits in USDA zone 7b, which sets what survives winter; the last 28°F hard freeze typically clears around Mar 4, with about 286 frost-free days to work with (NOAA 1991–2020 climate normals); and 2,016 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Sussex County average. Your yard writes its own version — 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.