One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Portola Valley it's a good idea to estimate when it's the best time to plant tomatos.

Planting Calendar for Tomatos

Frost tolerance for tomatos:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Tomatos are not cold tolerant which means that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant tomatos 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 tomatos and expect a good harvest is probably September. You probably don't want to wait any later than that or else your tomatos may not have a chance to really do well. You can get started a little bit earlier by starting your tomatos indoors.

Last Frost Date

The average date of last frost is January 31 in Portola Valley. It might get as low as 30°F during the coldest months of winter.

Keep in mind that USDA zone info for Portola Valley may not be accurate from year to year and the actual date of last frost can change quite a bit 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 cover your tomatos in the event of a surprise 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.