One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when it's the best time to plant penstemon in Minnetonka by reviewing the USDA zone info.

Planting Calendar for Penstemon

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

Penstemon are moderately cold tolerant which means that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant penstemon in Minnetonka 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. 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Minnetonka. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Minnetonka is an average and the actual date of last frost is different every year. Half of the time in Minnetonka there is a last frost after May 15 so just be sure to be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Minnetonka

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 Minnetonka

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