Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Maryville you should be able to figure out when you can 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 are one of those plants that can tolerate a little bit of cold weather you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant penstemon in Maryville 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 fully mature. Starting your penstemon indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Maryville. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Maryville is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Maryville there is a last frost after April 15 so just be sure to be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Maryville

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 Maryville

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