Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant regal geranium in Philadelphia should be figured out by reviewing the USDA zone info.

Planting Calendar for Regal Geranium

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

Since regal geranium do ok in moderate cold you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant regal geranium 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 regal geranium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your regal geranium may not have a chance to really do well. If you are starting your regal geranium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Philadelphia. It might get as low as 0°F during the coldest months of winter.

Always keep in mind that USDA zone info for Philadelphia may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Philadelphia last frost occurs after April 15 be ready to cover your regal geranium 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 Low	0°F
Highest Expected Low	5°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.