The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of estimating when to plant penstemon is to look at the USDA zone info for Donora.

Planting Calendar for Penstemon

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

Penstemon are moderately cold tolerant which tells us that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Donora 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 really do well. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Donora. In the coldest months of winter you can expect an average low temperature of -5°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Donora and it is different every year. Half of the time in Donora there is a last frost after April 15 so make sure that you are prepared to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Donora

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 Donora

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