Before planting it is a good idea to find your USDA Zone info to estimate 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 hibiscus in Philadelphia can be estimated by using the USDA zone info.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably not a good idea to plant hibiscus until after the last frost because they are not cold tolerant.

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

The last month that you can plant hibiscus and expect a good harvest is probably August. If you wait any later than that and your hibiscus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your hibiscus indoors.

Last Frost Date

In Philadelphia the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Philadelphia is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Philadelphia you get surprised by a frost after March 15 so just be sure to be ready to cover your hibiscus in the event of one of those late frosts.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Philadelphia

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