One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. 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 San Ramon should be read to estimate when it's a good idea to plant skullcap.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since skullcap require warm weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant skullcap in San Ramon is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant skullcap and expect a good harvest is probably September. If you wait any later than that and your skullcap may not have a chance to really do well. You can get started a little bit earlier by starting your skullcap indoors.

Last Frost Date

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

Since the USDA zone info for San Ramon is an average the actual date of last frost can change quite a bit from year to year. Half of the time in San Ramon you get a frost after February 15 so just be sure to be ready to cover your skullcap 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.