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.

In Philadelphia you can determine when to plant hardy hibiscus by looking at the USDA zone info.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus are very cold tolerant which means that you can plant them much earlier than more sensitive plants.

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

The last month that you can plant hardy hibiscus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy hibiscus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your hardy hibiscus indoors.

Last Frost Date

In Philadelphia the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 10°F.

Always keep in mind that USDA zone info for Philadelphia is not always accurate and the actual date of last frost is different every year. Since half of the time in Philadelphia you get a frost after March 15 be ready to cover your hardy hibiscus in the event of a late frost.

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.