Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. 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 string beans is to look at the USDA zone info for Marshalltown.

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.

Since string beans do not do well in cold weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant string beans in Marshalltown 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. You probably don't want to wait any later than that or else 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Marshalltown. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Marshalltown and it is different every year. Since half of the time in Marshalltown you get surprised by a frost after April 15 be ready to protect your string beans if you have one of those late frosts.

USDA Zone Info for Marshalltown

Here is the info for USDA Zone 5a.

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

Plants to Grow in Marshalltown

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