One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Mercer Island can be reffered to in order to determine when it's possible to plant string beans.

Planting Calendar for String beans

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

It's probably not a good idea to plant string beans until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant string beans in Mercer Island 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 string beans and expect a good harvest is probably August. Any later than that and your string beans may not have a chance to really do well. Starting your string beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Mercer Island. In the coldest months of winter you should expect an average low temperature of 15°F.

Always keep in mind that USDA zone info for Mercer Island may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Mercer Island there is a last frost after March 15 be ready to cover your string beans in the event of one of those late frosts.

USDA Zone Info for Mercer Island

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Mercer Island

You may be interested in your other planting guides for Mercer Island.