What Growing Zone Is Pennsylvania In?
USDA hardiness zones
5b to 7b
2023 USDA Plant Hardiness Zone Map
Pennsylvania spans USDA hardiness zone 5b to 7b 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.
Hardiness zone for ZIP 15222 (Pittsburgh)
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: Pittsburgh, PA
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).
Pennsylvania's USDA Hardiness Zones
Here's how the zone shifts across Pennsylvania'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 Pennsylvania
Frost dates track zone, so they shift across Pennsylvania the same way the zone number does:
- Northern tier/mountains (Bradford, Somerset) (zone 5): average last frost Apr 8 - Apr 22, average first frost Oct 8 - Oct 22.
- Southeastern corner (Philadelphia) (zone 7): average last frost Mar 18 - Apr 1, average first frost Oct 29 - Nov 12.
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 Pennsylvania's frost dates, see the Pennsylvania Planting Calendar.
Penn State Extension describes the state in three bands: "Zone 5 in most of the northern tier and mountainous areas where plants must be hardy to -20F to survive, Zone 6 in lower elevations where plants must tolerate temperatures down to -10F, and Zone 7 in the southeastern corner of the state where plants may face low temperatures of 0F."
What Grows Well in Pennsylvania's Zones
A few real, zone-appropriate picks recommended by Penn State Extension for Pennsylvania landscapes: not an exhaustive list, but a genuine starting point.
- Mountain laurel (state flower) (Kalmia latifolia)
- American holly (Ilex opaca)
- Inkberry (Ilex glabra)
- Japanese pieris (Pieris japonica)
- Oakleaf hydrangea (Hydrangea quercifolia)
Ready to find your exact zone? Use the Hardiness Zone Finder: enter your ZIP code for a precise match against the 2023 USDA map.
Pennsylvania Growing Zone FAQ
What growing zone is Pennsylvania in?
Pennsylvania spans USDA hardiness zones 5b to 7b on the 2023 USDA Plant Hardiness Zone Map. Bradford is zone 5b and Somerset is zone 5b; enter your ZIP code in the Hardiness Zone Finder for your exact zone.
What growing zone is Pittsburgh, PA?
Pittsburgh is in USDA hardiness zone 6b 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 Philadelphia, PA?
Philadelphia 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 Lancaster, PA?
Lancaster is in USDA hardiness zone 7a 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 Harrisburg, PA?
Harrisburg is in USDA hardiness zone 7a 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 Penn State Extension. Climate note sourced from Penn State Extension. 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:
- New York growing zones
- Ohio growing zones
- New Jersey growing zones
- Maryland growing zones
- West Virginia growing zones
- Delaware growing zones
Or browse all 51 state growing-zone guides.