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

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

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 frost tender plants.

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

Last Frost Date

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

It's important to remember 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 Smyrna and it is different every year. Since half of the time in Smyrna last frost occurs after April 15 be ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Smyrna

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 Smyrna

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