One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for San Francisco should be looked at to determine when it's a good idea to plant runner beans.

Planting Calendar for Runner beans

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

It's a bad idea to plant runner beans until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant runner beans in San Francisco 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 grow to maturity. Starting your runner beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Francisco the average date of last frost happens on January 31. In the coldest months of winter you should expect an average low temperature of 35°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Francisco and it changes from year to year. Half of the time in San Francisco it frosts late in the year after January 31 so make sure that you are prepared to protect your runner beans in the event of a late frost.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

You may be interested in your other planting guides for San Francisco.