Onslow County, in North Carolina, sits in USDA hardiness zone 8a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Expect sweet potato, blueberry, muscadine grape, and dogwood to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Onslow County lies within Tidewater & Chesapeake — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring
Onslow County holds more than one microclimate.
Soils and elevations shift across Onslow 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
8a
Last Frost (state avg.)
Mar 10 - May 5
First Frost (state avg.)
Oct 5 - Nov 15
County Area
488K acres
Hardiness Zone Range
Growing Season
Zone maps are averages across Onslow County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Onslow County
Across Onslow County, the ground is predominantly Ultisols, where Baymeade, Croatan, and Muckalee are the most extensive named soil series. The soil is generally poorly drained with a loamy fine sand surface. Topsoil pH runs about 4.5–5.5, very strongly acidic. Rainfall drains through hydrologic group A/D soils.
Soil order
Ultisols
Drainage
Poorly drained
Prime farmland
14%
Hydric soils
49%
Soil still varies lot by lot — soil types explained.
What Grows in Onslow County
Plants matched to Onslow County's USDA zones 8a — each links to its full growing profile.
Growing Challenges in North Carolina
What an experienced grower plans around here — each one has a move.
Red Piedmont clay is hard to work and drains poorly
Red clay rewards patience — compost opens it over seasons, and a raised bed gets you harvesting in the meantime.
Humidity drives significant disease pressure
Airflow, morning base-watering, and resistant varieties — the humid-South trio your extension's lists are built around.
Hurricane risk on the coastal plain
On the coastal plain, favor wind-tough perennials and stake young trees well ahead of storm season.
For cultivar selection, pest pressure, and planting-time guidance specific to North Carolina, the NC State Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Onslow County — and how to grow with it.
We checked the federal record across Onslow County — 550 documented sites across 7 of the 9 source types we track.
The most significant on record: 2 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Onslow County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
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.
Sources Checked
across Onslow County
Severity Distribution
across Onslow County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Onslow County, two things run higher than the national average — PFAS (5 sites) and Underground Storage Tanks (353 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Onslow 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
Onslow County Average
- ●USDA Zones 8a
- ●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 Onslow County
Pull a site-specific report for your exact address in Onslow County, North Carolina — 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 Onslow County, North Carolina
- USDA Hardiness Zones: 8a (USDA PHZM 2023)
- Last Spring Frost (state avg.): Mar 10 - May 5 (NOAA 30-Year Climate Normals)
- First Fall Frost (state avg.): Oct 5 - Nov 15 (NOAA 30-Year Climate Normals)
- County Land Area: 488K 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 Onslow 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 Onslow County, North Carolina?
Onslow County sits in USDA hardiness zone 8a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
When does frost risk typically end in Onslow County?
Onslow County follows North Carolina's statewide frost window: last spring frost around Mar 10 - May 5 and first fall frost around Oct 5 - Nov 15, per NOAA 30-year climate normals (1991–2020). Frost dates shift with elevation and local microclimate, so watch your own site's cold pockets.
What vegetables grow in Onslow County?
Onslow County's zone 8a supports a wide range — strong performers include Sweet Potato, Blueberry, Muscadine Grape, Dogwood, and Tomato. 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 Onslow County, really?
Officially, Onslow County sits in USDA zone 8a (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 Onslow County?
The federal record around Onslow County is a meaningful one — 550 documented sites — 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.
Just moved to Onslow County — what should I know before planting?
Start with three facts. Onslow County sits in USDA zone 8a, which sets what survives winter; the statewide frost window runs about Mar 10 - May 5 to Oct 5 - Nov 15 (NOAA 30-year climate normals); and 550 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 Onslow 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 North Carolina's frost window, season length, and soil profile against the plant's real requirements.