Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant potatos in Portola Valley can be determined by referring to the USDA zone info.

Planting Calendar for Potatos

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

You can plant potatos much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant potatos in Portola Valley 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 potatos and expect a good harvest is probably October. Any later than that and your potatos may not have a chance to fully mature. If you are starting your potatos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Portola Valley the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portola Valley and it will vary from year to year. Since half of the time in Portola Valley it frosts late in the year after January 31 be ready to cover your potatos 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.