One of the first steps you take when you are figuring out 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 reviewing the USDA zone info for Forest Park it's possible to estimate 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.

Since penstemon do well in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant penstemon in Forest Park 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 fully mature. 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 Forest Park. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Forest Park may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Forest Park you get surprised by a frost after April 15 so just be sure to be ready to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Forest Park

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 Forest Park

You may be interested in your other planting guides for Forest Park.