One of the best tools that you have as gardeners to help us figure out 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.

A common way of getting a good idea when to plant penstemon is to use the USDA zone info for Franklin.

Planting Calendar for Penstemon

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

Penstemon are one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Franklin 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. Starting your penstemon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Franklin the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Keep in mind that USDA zone info for Franklin is not always accurate and the actual date of last frost changes from year to year. Half of the time in Franklin it frosts late in the year after April 15 so make sure that you are ready to cover your penstemon if you have one of those late frosts.

USDA Zone Info for Franklin

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Franklin

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