One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when you can plant purple coneflower by reviewing the USDA zone info for Philadelphia.

Planting Calendar for Purple Coneflower

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

Since purple coneflower are barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant purple coneflower 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 purple coneflower and expect a good harvest is probably August. If you wait any later than that and your purple coneflower may not have a chance to grow to maturity. If you are starting your purple coneflower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Philadelphia the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Philadelphia and it is different every year. Since half of the time in Philadelphia it frosts late in the year after April 15 be ready to cover your purple coneflower if you have 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.