Before planting it is a good idea to find your USDA Zone info to estimate 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.

The first opportunity to plant penstemon in Okmulgee should be figured out by looking at the USDA zone info.

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 frost tender plants.

The earliest that you can plant penstemon in Okmulgee 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. 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 Okmulgee the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

It's important to remember that USDA zone info for Okmulgee is an average and the actual date of last frost is different every year. Half of the time in Okmulgee there is a last frost after April 15 so always be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Okmulgee

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Okmulgee

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