What Growing Zone Is Delaware In?
USDA hardiness zones
7b to 8a
2023 USDA Plant Hardiness Zone Map
Delaware spans USDA hardiness zone 7b to 8a across its major population centers, according to the 2023 USDA Plant Hardiness Zone Map. That's a real range, not a single number: where you fall in it depends on where in the state you actually are.
Find your exact zone
Your USDA hardiness zone
Zone 6b
Avg. annual minimum (°F)
-5°F to 0°F
Avg. annual minimum (°C)
-21°C to -18°C
Nearest reference point: Chicago, IL
This is a regional estimate based on the nearest of 826 reference points, each matched to the official 2023 USDA zone map. It’s accurate to within about a half-zone across most of the country, but elevation shifts zones over short distances, so if you’re in mountainous terrain, check the official USDA map for your exact address (see Sources below).
Delaware's USDA Hardiness Zones
Here's how the zone shifts across Delaware's major cities:
For your exact zone by ZIP code, use the Hardiness Zone Finder, and for what a zone number actually measures (and doesn't), see how zones actually work.
Frost Dates in Delaware
Frost dates track zone, so they shift across Delaware the same way the zone number does:
- Northern Delaware (Wilmington, Dover) (zone 7): average last frost Mar 18 - Apr 1, average first frost Oct 29 - Nov 12.
- Coastal Sussex County (Rehoboth Beach) (zone 8): average last frost Mar 8 - Mar 22, average first frost Nov 8 - Nov 22.
These are averages, not guarantees. For your specific frost window, use the Frost Date Calculator. For a full vegetable-by-vegetable planting calendar already calculated from Delaware's frost dates, see the Delaware Planting Calendar.
Delaware's small size still carries a coastal-moderation effect: mean annual temperature runs from about 54.0F in Wilmington up to roughly 58.1F near the Rehoboth Beach area, per the University of Delaware's climate office.
What Grows Well in Delaware's Zones
A few real, zone-appropriate picks recommended by University of Delaware Cooperative Extension for Delaware landscapes: not an exhaustive list, but a genuine starting point.
- Sweetbay magnolia (Magnolia virginiana)
- Flowering dogwood (Cornus florida)
- Eastern redbud (Cercis canadensis)
- American holly (Ilex opaca)
- Summersweet clethra (Clethra alnifolia)
- Winterberry (Ilex verticillata)
Ready to find your exact zone? Use the Hardiness Zone Finder: enter your ZIP code for a precise match against the 2023 USDA map.
Delaware Growing Zone FAQ
What growing zone is Delaware in?
Delaware spans USDA hardiness zones 7b to 8a on the 2023 USDA Plant Hardiness Zone Map. Wilmington is zone 7b and Dover is zone 7b; enter your ZIP code in the Hardiness Zone Finder for your exact zone.
What growing zone is Wilmington, DE?
Wilmington is in USDA hardiness zone 7b on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is Dover, DE?
Dover is in USDA hardiness zone 7b on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is Georgetown, DE?
Georgetown is in USDA hardiness zone 7b on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
What growing zone is Rehoboth Beach, DE?
Rehoboth Beach is in USDA hardiness zone 8a on the 2023 USDA map. Zones within a city can differ by half a zone, so check your ZIP code for an exact match.
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The Spacing & Planting Cheat Sheet
When to start, when to plant, how far apart.
Sources & further reading
Zone and city data checked against the official USDA Plant Hardiness Zone Map. Plant recommendations sourced from University of Delaware Cooperative Extension. Climate note sourced from University of Delaware, DEOS Climate Office. For more on how we build and verify reference data across this site, see our methodology page.
Growing zones in nearby states
Gardening near a state line? Zones don't stop at the border:
Or browse all 51 state growing-zone guides.