The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's possible to plant penstemon is to refer to the USDA zone info for Mount Horeb.

Planting Calendar for Penstemon

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

Penstemon tend to make it in mild cold which means that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Mount Horeb 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 little bit earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Mount Horeb. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Mount Horeb is an average the actual date of last frost changes from year to year. Half of the time in Mount Horeb you get surprised by a frost after April 15 so make sure that you are prepared to protect your penstemon if you have a late frost.

USDA Zone Info for Mount Horeb

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Mount Horeb

You may be interested in your other planting guides for Mount Horeb.