One of the best tools that you have as gardeners to help us figure out 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.

A common way of figuring out when it's possible to plant penstemon is to use the USDA zone info for Zone 10a.

Planting Calendar for Penstemon

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

Since penstemon do well in moderate cold you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant penstemon in Zone 10a 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. Starting your penstemon indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Zone 10a. In the coldest months of winter you can expect an average low temperature of 30°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Zone 10a and it can change quite a bit from year to year. Half of the time in Zone 10a it frosts late in the year after January 31 so make sure that you are prepared to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Zone 10a

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 Zone 10a

You may be interested in your other planting guides for Zone 10a.