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.

By looking at the USDA zone info for Doylestown you will be able to figure out when it's the best time to plant penstemon.

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 tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Doylestown 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. You probably don't want to wait any later than that or else your penstemon may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

In Doylestown 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.

Keep in mind that USDA zone info for Doylestown is just an average and the actual date of last frost changes from year to year. Since half of the time in Doylestown it frosts late in the year after April 15 be ready to cover your penstemon if you have a surprise late frost.

USDA Zone Info for Doylestown

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 Doylestown

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