One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. 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 a good idea to plant penstemon is to look at the USDA zone info for Rexburg.

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 means that you can start planting them earlier than plants that are more sensitive to the cold.

The earliest that you can plant penstemon in Rexburg 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. If you wait any later than that and your penstemon may not have a chance to fully mature. Starting your penstemon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Rexburg. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Rexburg is an average the actual date of last frost changes from year to year. Since half of the time in Rexburg it frosts late in the year after April 15 be ready to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Rexburg

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 Rexburg

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