Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of estimating when you can plant penstemon is to refer to the USDA zone info for Oak Grove.

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 little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant penstemon in Oak Grove 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 really do well. If you are starting your penstemon indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Oak Grove. In the coldest months of winter you should expect an average low temperature of -10°F.

Just be sure to remember that USDA zone info for Oak Grove is an average and the actual date of last frost changes from year to year. Since half of the time in Oak Grove last frost occurs after April 15 be ready to protect your penstemon in the event of a surprise late frost.

USDA Zone Info for Oak Grove

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 Oak Grove

You may be interested in your other planting guides for Oak Grove.