One of the first steps you take when you are getting a good idea 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.

A way of getting a good idea when it's the best time to plant basil is to use the USDA zone info for San Ramon.

Planting Calendar for Basil

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

You should not plant basil until after the last frost because they are not cold tolerant.

The earliest that you can plant basil 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 basil and expect a good harvest is probably September. If you wait any later than that and your basil may not have a chance to really do well. If you are starting your basil indoors then you might be able to get away with starting them a few weeks earlier.

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.

Remember that USDA zone info for San Ramon is an average and the actual date of last frost is different every year. Since half of the time in San Ramon you get surprised by a frost after February 15 be ready to protect your basil 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.