The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when it's possible to plant penstemon is to examine the USDA zone info for Bozeman.

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 some cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant penstemon in Bozeman 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. You probably don't want to wait any later than that or else 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

On average all chance of frost has passed is on May 15 in Bozeman. You can expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that USDA zone info for Bozeman is an average and the actual date of last frost is different every year. Since half of the time in Bozeman you get surprised by a frost after May 15 be ready to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Bozeman

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 Bozeman

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