Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 to plant scarlet runner beans by referring to the USDA zone info for Sunnyvale.

Planting Calendar for Scarlet Runner Beans

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

Since scarlet runner beans do not do well in cold weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant scarlet runner beans in Sunnyvale is April. However, you really should wait until May 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 August. If you wait any later than that and your scarlet runner beans may not have a chance to grow to maturity. If you are starting your scarlet runner beans indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Sunnyvale the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

It's important to remember that USDA zone info for Sunnyvale is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Sunnyvale it frosts late in the year after March 15 be ready to cover your scarlet runner beans if you have one of those late frosts.

USDA Zone Info for Sunnyvale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Sunnyvale

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