One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The USDA zone info for Stockton should be reffered to in order to figure out when you can 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 do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant penstemon in Stockton 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 couple of weeks earlier by starting your penstemon indoors.

Last Frost Date

On average the last frost is on February 15 in Stockton. It might get as low as 25°F during the coldest months of winter.

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

USDA Zone Info for Stockton

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 Stockton

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