The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Napa should be used to figure out when it's the best time to plant scarlet runner beans.

Planting Calendar for Scarlet Runner Beans

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

Scarlet Runner Beans are not cold tolerant which means that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant scarlet runner beans in Napa 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. You probably don't want to wait any later than that or else your scarlet runner beans may not have a chance to really do well. Starting your scarlet runner beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Napa is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Napa it frosts late in the year after February 15 be ready to protect your scarlet runner beans if you have a surprise late frost.

USDA Zone Info for Napa

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 Napa

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