One of the first steps you take when you are determining 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.

A way of making a decision about when it's possible to plant begonias is to look at the USDA zone info for Philadelphia.

Planting Calendar for Begonias

Frost tolerance for begonias:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant begonias until after the last frost because they require warm weather.

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

Last Frost Date

On average the last frost is on March 15 in Philadelphia. You can expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Philadelphia is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Philadelphia last frost occurs after March 15 be ready to cover your begonias in the event of a 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.