One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when you can plant xerianthemum is to check out the USDA zone info for Philadelphia.

Planting Calendar for Xerianthemum

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

You can plant xerianthemum slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant xerianthemum 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 xerianthemum and expect a good harvest is probably August. If you wait any later than that and your xerianthemum may not have a chance to really do well. Starting your xerianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Philadelphia and it changes from year to year. Half of the time in Philadelphia you get a frost after April 15 so make sure that you are prepared to protect your xerianthemum in the event of a 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.