When to Plant Penstemon in Owosso, MI

One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

You can determine when it's a good idea to plant penstemon in Owosso by using 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.

You can plant penstemon a little bit earlier in the year because they are moderately cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant penstemon
Possibly ok, but a risky time to plant penstemon
Probably not a good time to plant penstemon

The earliest that you can plant penstemon in Owosso 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. You probably don't want to wait any later than that or else your penstemon may not have a chance to really do well. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

The average date of last frost is April 15 in Owosso. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Owosso is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Owosso it frosts late in the year after April 15 be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Owosso

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Owosso

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