One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when it's possible to plant scarlet runner beans in Washington by using the USDA zone info.

Planting Calendar for Scarlet Runner Beans

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

Since scarlet runner beans are not cold tolerant it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant scarlet runner beans in Washington 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. Any later than that and your scarlet runner beans may not have a chance to really do well. If you are starting your scarlet runner beans indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Washington the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Washington may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Washington it frosts late in the year after March 15 so be sure to be ready to protect your scarlet runner beans if you have one of those late frosts.

USDA Zone Info for Washington

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 Washington

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