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 way of estimating when you can plant rosemary is to consult the USDA zone info for San Ramon.

Planting Calendar for Rosemary

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

Rosemary do well in quite a bit of cold which means that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in San Ramon 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 rosemary and expect a good harvest is probably October. You probably don't want to wait any later than that or else your rosemary may not have a chance to grow to maturity. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

In San Ramon the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for San Ramon may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in San Ramon there is a last frost after February 15 be ready to cover your rosemary in the event of a late frost.

USDA Zone Info for San Ramon

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 San Ramon

You may be interested in your other planting guides for San Ramon.