When to Plant Petunias in Philadelphia, PA

One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Philadelphia you should be able to determine when to plant petunias.


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 are barely cold tolerant which tells us that you can get them planted just a bit earlier than more sensitive 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 Philadelphia 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. If you wait any later than that and your petunias may not have a chance to really do well. Starting your petunias indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Philadelphia the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Philadelphia and it is different every year. Half of the time in Philadelphia it frosts late in the year after April 15 so make sure that you are ready to protect your petunias if you have a surprise late frost.

USDA Zone Info for Philadelphia

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 Philadelphia

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