The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of determining when to plant penstemon is to examine the USDA zone info for Del Rio.

Planting Calendar for Penstemon

Frost tolerance for penstemon:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant penstemon a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant penstemon in Del Rio is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant penstemon and expect a good harvest is probably October. You probably don't want to wait any later than that or else your penstemon may not have a chance to really do well. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

In Del Rio the average date of last frost happens on February 15. You should expect an average low temperature of 20°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Del Rio and it will vary from year to year. Since half of the time in Del Rio there is a last frost after February 15 be ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Del Rio

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Del Rio

You may be interested in your other planting guides for Del Rio.