One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Philadelphia can be used to determine when it's the best time to plant rudbeckia.

Planting Calendar for Rudbeckia

Frost tolerance for rudbeckia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since rudbeckia are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant rudbeckia 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 rudbeckia and expect a good harvest is probably September. Any later than that and your rudbeckia may not have a chance to really do well. Starting your rudbeckia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Philadelphia is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Philadelphia it frosts late in the year after April 15 be ready to protect your rudbeckia in the event of 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.