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.

It's a good idea to determine when it's the best time to plant runner beans by using the USDA zone info for Portola Valley.

Planting Calendar for Runner beans

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

You should not plant runner beans until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant runner beans 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 runner beans and expect a good harvest is probably September. Any later than that and your runner beans may not have a chance to really do well. Starting your runner beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Portola Valley. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Portola Valley is an average the actual date of last frost is different every year. Half of the time in Portola Valley last frost occurs after January 31 so be sure to be ready to protect your runner beans if you have one of those late frosts.

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.