One of the first steps you take when you are figuring out 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.

You should be able to figure out when it's the best time to plant scarlet runner beans by looking at the USDA zone info for Mill Valley.

Planting Calendar for Scarlet Runner Beans

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

You can not plant scarlet runner beans until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant scarlet runner beans in Mill 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 scarlet runner beans and expect a good harvest is probably September. If you wait any later than that and your scarlet runner beans may not have a chance to fully mature. Starting your scarlet runner beans indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on January 31 in Mill Valley. You should expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that USDA zone info for Mill Valley is just an average and the actual date of last frost changes from year to year. Since half of the time in Mill Valley you get surprised by a frost after January 31 be ready to protect your scarlet runner beans in the event of one of those late frosts.

USDA Zone Info for Mill 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 Mill Valley

You may be interested in your other planting guides for Mill Valley.