One of the first steps you take when you are figuring out 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.

The earliest that you can plant aubrieta in Philadelphia should be estimated by using the USDA zone info.

Planting Calendar for Aubrieta

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

Aubrieta do well in a little bit of cold which means that you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant aubrieta 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 aubrieta and expect a good harvest is probably September. If you wait any later than that and your aubrieta may not have a chance to grow to maturity. Starting your aubrieta indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Keep in mind 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 last frost occurs after March 15 be ready to protect your aubrieta if you have one of those late frosts.

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.