One of the first steps you take when you are estimating 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.

You will be able to determine when to plant penstemon by checking out the USDA zone info for Coldwater.

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 Coldwater 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. If you wait any later than that and your penstemon may not have a chance to really do well. If you are starting your penstemon indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Coldwater is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Coldwater there is a last frost after April 15 be ready to cover your penstemon in the event of a late frost.

USDA Zone Info for Coldwater

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Coldwater

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