One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Blackwell should be read to estimate when it's the best time 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 are moderately cold tolerant which means that you can start planting them earlier than more sensitive plants.

The earliest that you can plant penstemon in Blackwell 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 really do well. Starting your penstemon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Blackwell. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Blackwell is an average the actual date of last frost will vary from year to year. Half of the time in Blackwell you get a frost after April 15 so make sure that you are prepared to cover your penstemon if you have a late frost.

USDA Zone Info for Blackwell

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 Blackwell

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