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.

The USDA zone info for Highland can be read to figure out when it's possible 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 moderately cold tolerant which means that you can start planting them earlier than other frost tender plants.

The earliest that you can plant penstemon in Highland 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. If you are starting your penstemon indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Highland the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Highland and it changes from year to year. Since half of the time in Highland you get surprised by a frost after April 15 be ready to cover your penstemon if you have one of those late frosts.

USDA Zone Info for Highland

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 Highland

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