Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to estimate when it's possible to plant penstemon by reviewing the USDA zone info for Carthage.

Planting Calendar for Penstemon

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

Since penstemon are moderately cold tolerant you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant penstemon in Carthage 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. If you are starting your penstemon indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Carthage is just an average and the actual date of last frost will vary from year to year. Half of the time in Carthage you get a frost after April 15 so always be ready to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Carthage

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 Carthage

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