Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Vacaville it's possible to determine when it's the best time to plant penstemon.

Planting Calendar for Penstemon

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

Since penstemon are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant penstemon in Vacaville 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. Any later than that and your penstemon may not have a chance to fully mature. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost is on February 15 in Vacaville. You should expect an average low temperature of 25°F in the coldest months of winter.

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

USDA Zone Info for Vacaville

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Vacaville

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