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.

The earliest that you can plant penstemon in Rohnert Park should be determined by looking at the USDA zone info.

Planting Calendar for Penstemon

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

Penstemon tend to make it in moderate cold which means that 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 Rohnert Park 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 grow to maturity. If you are starting your penstemon indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rohnert Park and it will vary from year to year. Since half of the time in Rohnert Park you get a frost after February 15 be ready to cover your penstemon in the event of a surprise late frost.

USDA Zone Info for Rohnert Park

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 Rohnert Park

You may be interested in your other planting guides for Rohnert Park.