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.

By referring to the USDA zone info for Shenandoah you should be able to determine when it's a good idea 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 do well in a little bit of cold which means that you can plant them a little bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant penstemon in Shenandoah 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. Any later than that and your penstemon may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Shenandoah. It might get as low as -10°F during the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Shenandoah and it can change quite a bit from year to year. Since half of the time in Shenandoah 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 Shenandoah

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 Shenandoah

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