One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Philadelphia you should be able to figure out when it's possible to plant pennisetum.

Planting Calendar for Pennisetum

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

Pennisetum can survive in very little cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant pennisetum 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 pennisetum and expect a good harvest is probably August. If you wait any later than that and your pennisetum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your pennisetum indoors.

Last Frost Date

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

Since the USDA zone info for Philadelphia is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Philadelphia there is a last frost after March 15 be ready to cover your pennisetum in the event of a surprise 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.