Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when to plant penstemon by looking at the USDA zone info for Lake Elmo.

Planting Calendar for Penstemon

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

Penstemon can survive in moderate cold which means that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Lake Elmo 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. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

The average date of last frost is May 15 in Lake Elmo. It might get as low as -25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Lake Elmo and it will vary from year to year. Since half of the time in Lake Elmo there is a last frost after May 15 be ready to protect your penstemon if you have a late frost.

USDA Zone Info for Lake Elmo

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 Lake Elmo

You may be interested in your other planting guides for Lake Elmo.