One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's the best time to plant penstemon by using the USDA zone info for La Mesa.

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 start planting them earlier than other frost tender plants.

The earliest that you can plant penstemon in La Mesa 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 fully mature. You can get started a little bit earlier by starting your penstemon indoors.

Last Frost Date

The average date of last frost is January 31 in La Mesa. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for La Mesa is an average the actual date of last frost can change quite a bit from year to year. Half of the time in La Mesa you get surprised by a frost after January 31 so make sure that you are ready to cover your penstemon in the event of a late frost.

USDA Zone Info for La Mesa

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in La Mesa

You may be interested in your other planting guides for La Mesa.