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 reffered to in order to figure out when it's a good idea to plant aubretia.

Planting Calendar for Aubretia

Frost tolerance for aubretia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Aubretia do well in cold which tells us that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant aubretia 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 aubretia and expect a good harvest is probably September. Any later than that and your aubretia may not have a chance to really do well. If you are starting your aubretia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Philadelphia. In the coldest months of winter you can expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Philadelphia and it will vary from year to year. Since half of the time in Philadelphia there is a last frost after March 15 be ready to protect your aubretia in the event of a surprise late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Philadelphia

You may be interested in your other planting guides for Philadelphia.