The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Troy you will be able to determine when 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.

You can plant penstemon just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant penstemon in Troy 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 little bit earlier by starting your penstemon indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Troy may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Troy there is a last frost after April 15 so always be ready to cover your penstemon in the event of one of those late frosts.

USDA Zone Info for Troy

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 Troy

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