When to Plant Petunias in Mechanicsburg, PA

Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when you can plant petunias by referring to the USDA zone info for Mechanicsburg.


Planting Calendar for Petunias

Frost tolerance for petunias: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Petunias do ok in moderate cold which means that you can start planting them slightly earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant petunias
Possibly ok, but a risky time to plant petunias
Probably not a good time to plant petunias

The earliest that you can plant petunias in Mechanicsburg is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant petunias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your petunias may not have a chance to fully mature. If you are starting your petunias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Mechanicsburg. You can expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mechanicsburg and it changes from year to year. Since half of the time in Mechanicsburg you get a frost after April 15 be ready to cover your petunias in the event of one of those late frosts.

USDA Zone Info for Mechanicsburg

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low0°F
Highest Expected Low5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Mechanicsburg

You may be interested in your other planting guides for Mechanicsburg.