Before planting it is a good idea to find your USDA Zone info to estimate 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.

The USDA zone info for Mitchell should be reffered to in order 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 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 Mitchell is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant penstemon and expect a good harvest is probably August. If you wait any later than that and your penstemon may not have a chance to fully mature. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

In Mitchell the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Mitchell may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Mitchell there is a last frost after May 15 so always be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Mitchell

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Mitchell

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