The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to determine when it's possible to plant penstemon by using the USDA zone info for Stafford.

Planting Calendar for Penstemon

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

Penstemon do well in moderate cold which means that you can get them planted earlier than more sensitive plants.

The earliest that you can plant penstemon in Stafford 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. If you wait any later than that and your penstemon may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Stafford. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Stafford is just an average the actual date of last frost changes from year to year. Half of the time in Stafford you get a frost after February 15 so always be ready to protect your penstemon if you have one of those late frosts.

USDA Zone Info for Stafford

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 Stafford

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