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.

A way of estimating when to plant balloon flower is to consult the USDA zone info for Philadelphia.

Planting Calendar for Balloon Flower

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

Balloon Flower can survive in some cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant balloon flower 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 balloon flower and expect a good harvest is probably August. If you wait any later than that and your balloon flower may not have a chance to fully mature. You can get started a few weeks earlier by starting your balloon flower indoors.

Last Frost Date

On average the last frost is on April 15 in Philadelphia. In the coldest months of winter you should expect an average low temperature of 0°F.

Keep in mind that USDA zone info for Philadelphia is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Philadelphia it frosts late in the year after April 15 be ready to cover your balloon flower in the event of one of those late frosts.

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.