One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Detroit Lakes can be read to estimate when it's the best time to plant penstemon.

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 tells us that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant penstemon in Detroit Lakes 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 grow to maturity. You can get started a little bit earlier by starting your penstemon indoors.

Last Frost Date

The average date of last frost is May 15 in Detroit Lakes. In the coldest months of winter you can expect an average low temperature of -35°F.

Keep in mind that USDA zone info for Detroit Lakes is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Detroit Lakes last frost occurs after May 15 so make sure that you are prepared to protect your penstemon in the event of a surprise late frost.

USDA Zone Info for Detroit Lakes

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Detroit Lakes

You may be interested in your other planting guides for Detroit Lakes.