One of the first steps you take when you are making a decision about 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 determining when it's possible to plant scarlet runner beans is to use the USDA zone info for Sonora.

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.

Scarlet Runner Beans do not do well in cold weather which tells us that you need to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant scarlet runner beans in Sonora 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. 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 little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Sonora. In the coldest months of winter you should expect an average low temperature of 20°F.

Remember that USDA zone info for Sonora may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Sonora you get a frost after February 15 so just be sure to be ready to cover your scarlet runner beans in the event of a late frost.

USDA Zone Info for Sonora

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sonora

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