One of the best tools that you have as gardeners to help us determine 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 should be reffered to in order to determine when it's the best time to plant schizanthus.

Planting Calendar for Schizanthus

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

Since schizanthus require warm weather it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant schizanthus 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 schizanthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your schizanthus may not have a chance to fully mature. Starting your schizanthus indoors is a great way to get them started a couple of weeks 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.

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 will vary from year to year. Half of the time in Philadelphia you get a frost after April 15 so be sure to be ready to protect your schizanthus in the event of one of those late frosts.

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.