When to Plant Petunias in Norristown, PA

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Norristown you can determine when you can plant petunias by checking out the USDA zone info.


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.

Since petunias are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

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 Norristown 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. Starting your petunias indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Norristown is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Norristown you get surprised by a frost after April 15 so always be ready to cover your petunias if you have a surprise late frost.

USDA Zone Info for Norristown

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 Norristown

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