Most of Pennsylvania is in planting zones 6a, 6b, 7a, and 7b, meaning the average lowest temperatures range between -10 to -5 degrees (6a) and 5 to 10 degrees (7b).
Understanding your gardening zone helps you select the best plants and grass for your area. Keep reading to learn more about each planting zone in Pennsylvania and how it affects your gardening and lawn care.
Overview of Pennsylvania growing zones
Although most of Pennsylvania is in zones 6a to 7b, some areas are in zone 5b, with average winter lows ranging from -15 to -10 degrees Fahrenheit. These include sections of northern Pennsylvania and a small segment in the southeast. A much smaller section of the state is in zone 8a, with the lowest temperatures averaging between 10 to 15 degrees Fahrenheit.
Our guide How to Use the Plant Hardiness Zone Map in Your Yard will tell you everything you need to know to use zoning information to build and maintain a healthy and thriving landscape.
Zones 5b to 7a: Western Pennsylvania
Western Pennsylvania is in zones 5b to 7a, with most of the region in zones 6a and 6b. This means the lowest average temperatures for most of Western Pennsylvania range between -10 to 5 degrees Fahrenheit (6a) and -5 to 0 degrees Fahrenheit (6b). This region has warm, humid summers and cold, snowy winters.
First and last frost dates vary per city. Major cities, like Altoona and Erie, experience the first frost around mid to late October and the last frost around early May. Pittsburg can experience the last frost date as early as the end of April. In general, the average first frost date for Western Pennsylvania is around October 15, and the average last frost date is May 15th.
The growing season is about 173 days on average.
Lawn Love’s guide, Planting Zones of Western Pennsylvania, goes into more depth about planting zones 5b to 7a.
Planting zones by city:
- Altoona – 6b
- Erie – 7a
- Johnstown – 6b
- Pittsburgh – 7a
Zones 5b to 7a: Central Pennsylvania
Central Pennsylvania is in zones 5b to 7a, with most of the region in zones 6a to 7a. The lowest winter temperatures for most of this region average between -10 to -5 (zone 6a) and 0 to 5 degrees Fahrenheit (zone 7a). The summers are warm to hot with cold winters and moderate snowfall. The last frost dates average between April 21 and May 1, while the average first frost occurs around October 11 through October 20.
The growing season is an average of about 170 days.
If you want more information on how planting these zones affects you, our article, Planting Zones of Central Pennsylvania, goes into more detail.
Planting zones by city:
- Carlisle – 7a
- Harrisburg – 7a
- State College – 6b
- Williamsport – 6b
Zone 5b to 7a: Northeast Pennsylvania
Northeast Pennsylvania is mostly in zones 5b through 7a, meaning the lowest average temperature stretches from -15 to -10 degrees Fahrenheit to 0 to 5 degrees Fahrenheit. The climate is humid with cooler summers than the rest of the state. Winters are cold and can sometimes have heavy snowfall.
The last frost is typically between April 30 and May 14. Some larger locations like Scranton and Wilkes-Barre have a last frost date of April 30 and a first frost date of Oct 13. Other cities, like Nanticoke and Hazleton, have the last frost dates between May 7 and May 14, and the first frost dates between October 1 and October 13.
The growing season is relatively short, averaging about 157 days.
Lawn Love tells you more in our guide Planting Zones of Northeast Pennsylvania.
Planting zones by city:
- Hazleton – 6b
- Scranton – 6b
- Wilkes-Barre – 7a
Zones 6b to 8a: Southeastern Pennsylvania
Southern Pennsylvania stretches across zones 6b through 8a, but most of this corner of the state is in zones 7a and 7b. This means most of the region experiences average lowest temperatures between 0 and 5 degrees Fahrenheit (zone 7a) and 5 to 10 degrees Fahrenheit (zone 7b).
Summers are warm with some high temperatures, and winters are cold but typically mild. Southeastern Pennsylvania has hotter summers than other regions like the northwest, and the southwestern corner has the warmest climate in the state.
Average last frost dates are typically between April 4 and April 26, with average first frost dates between October 17 and November 11. The growing season can last an average of around 173 days or an average of about 220 days.
Learn more about the zones in this corner of the state in our article, Planting Zones of Southeastern Pennsylvania.
Planting zones by city:
- Allentown – 7a
- Philadelphia – 7b
- Reading – 7a
For more about lawn care and landscaping in Pennsylvania, check out these guides:
- 10 Best Native Plants for Philadelphia
- 9 Best Native Plants for Your Pittsburgh Yard
- The Best Grass Seed for Pennsylvania Lawns
- When to Aerate Your Lawn in Pennsylvania
- When to Dethatch Your Lawn in Pennsylvania
- When to Stop Mowing Your Lawn in Pennsylvania
Call a professional
Knowing your planting zone can be the difference between a yard full of thriving plants and a yard full of vegetation that is not hardy enough to survive local conditions. You don’t have to be an expert on planting zones and other factors that influence whether you have healthy plants and grass. Lawn Love has qualified professionals to manage your garden and lawn.
Main Photo Credit: Djmaschek | Wikimedia Commons | CC BY-SA 4.0
Related Posts:
