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.

By looking at the USDA zone info for Portola Valley you will be able to determine when it's the best time to plant basil.

Planting Calendar for Basil

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

Basil do not do well in cold weather which means that it's important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant basil in Portola Valley is February. However, you really should wait until March 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 fully mature. You can get started a couple of weeks earlier by starting your basil indoors.

Last Frost Date

In Portola Valley the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Portola Valley is not always accurate the actual date of last frost will vary from year to year. Half of the time in Portola Valley it frosts late in the year after January 31 so always be ready to protect your basil in the event of a late frost.

USDA Zone Info for Portola Valley

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Portola Valley

You may be interested in your other planting guides for Portola Valley.