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.

In Decorah you can estimate when to plant scarlet runner beans 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.

Scarlet Runner Beans are not cold tolerant which tells us that it's important 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 Decorah 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. Any later than that and 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

The average date of last frost is May 15 in Decorah. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Decorah may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Decorah you get surprised by a frost after May 15 be ready to cover your scarlet runner beans in the event of a surprise late frost.

USDA Zone Info for Decorah

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 Decorah

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