One of the best tools that you have as gardeners to help us figure out 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.

By checking out the USDA zone info for Watertown you should be able 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.

You can not plant scarlet runner beans until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant scarlet runner beans in Watertown is May. However, you really should wait until June 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 fully mature. 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

On average the last frost has passed is on May 15 in Watertown. It might get as low as -25°F during the coldest months of winter.

Remember that USDA zone info for Watertown is just an average and the actual date of last frost changes from year to year. Since half of the time in Watertown it frosts late in the year after May 15 be ready to protect your scarlet runner beans if you have one of those late frosts.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Watertown

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