Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant chrysocephalum in Philadelphia can be figured out by using the USDA zone info.

Planting Calendar for Chrysocephalum

Frost tolerance for chrysocephalum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You should not plant chrysocephalum until after the last frost because they are not cold tolerant.

The earliest that you can plant chrysocephalum in Philadelphia is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant chrysocephalum and expect a good harvest is probably August. Any later than that and your chrysocephalum may not have a chance to really do well. If you are starting your chrysocephalum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Philadelphia. You should expect an average low temperature of 0°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. Half of the time in Philadelphia last frost occurs after April 15 so just be sure to be ready to cover your chrysocephalum if you have 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.