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.

You will be able to determine when you can plant penstemon by reviewing the USDA zone info for Allen.

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 tells us that you can get them planted earlier than more sensitive plants.

The earliest that you can plant penstemon in Allen 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 fully mature. You can get started a couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

The average date of last frost is March 15 in Allen. In the coldest months of winter you should expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Allen and it can change quite a bit from year to year. Half of the time in Allen last frost occurs after March 15 so make sure that you are ready to protect your penstemon if you have a surprise late frost.

USDA Zone Info for Allen

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Allen

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