One of the best tools that you have as gardeners to help us determine 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 figuring out when you can plant penstemon is to check out the USDA zone info for Souderton.

Planting Calendar for Penstemon

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

Penstemon do well in moderate cold which means that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Souderton 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 penstemon and expect a good harvest is probably September. Any later than that and your penstemon may not have a chance to fully mature. You can get started a little bit earlier by starting your penstemon indoors.

Last Frost Date

In Souderton the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Souderton is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Souderton there is a last frost after April 15 so be sure to be ready to protect your penstemon in the event of a late frost.

USDA Zone Info for Souderton

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Souderton

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