One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In San Bruno you can figure out when you can plant scarlet runner beans by referring to the USDA zone info.

Planting Calendar for Scarlet Runner Beans

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

Since scarlet runner beans are not cold tolerant you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant scarlet runner beans in San Bruno 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 scarlet runner beans and expect a good harvest is probably September. Any later than that and your scarlet runner beans may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your scarlet runner beans indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in San Bruno. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for San Bruno is not always accurate the actual date of last frost is different every year. Half of the time in San Bruno it frosts late in the year after January 31 so make sure that you are ready to protect your scarlet runner beans if you have a surprise late frost.

USDA Zone Info for San Bruno

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 San Bruno

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