The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Santa Rosa can be reviewed to estimate when it's the best time to plant fennel.

Planting Calendar for Fennel

Frost tolerance for fennel:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since fennel do well in cold you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant fennel in Santa Rosa 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 fennel and expect a good harvest is probably October. You probably don't want to wait any later than that or else your fennel may not have a chance to fully mature. If you are starting your fennel 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 when the weather gets warmer is on February 15 in Santa Rosa. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Santa Rosa is not always accurate the actual date of last frost will vary from year to year. Half of the time in Santa Rosa there is a last frost after February 15 so make sure that you are ready to protect your fennel in the event of a late frost.

USDA Zone Info for Santa Rosa

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 Santa Rosa

You may be interested in your other planting guides for Santa Rosa.