One of the first steps you take when you are getting a good idea 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.

A common way of getting a good idea when it's the best time to plant scarlet runner beans is to use the USDA zone info for Cupertino.

Planting Calendar for Scarlet Runner Beans

Frost tolerance for scarlet runner beans:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant scarlet runner beans until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant scarlet runner beans in Cupertino is March. However, you really should wait until April 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 really do well. You can get started a few weeks earlier by starting your scarlet runner beans indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Cupertino. In the coldest months of winter you should expect an average low temperature of 25°F.

It's important to remember that USDA zone info for Cupertino is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Cupertino you get surprised by a frost after February 15 so always be ready to protect your scarlet runner beans in the event of one of those late frosts.

USDA Zone Info for Cupertino

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Cupertino

You may be interested in your other planting guides for Cupertino.