The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 Grinnell should be read to estimate when you can plant runner beans.

Planting Calendar for Runner beans

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

Since runner beans do not do well in cold weather it's important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant runner beans in Grinnell 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 runner beans and expect a good harvest is probably August. You probably don't want to wait any later than that or else your runner beans may not have a chance to really do well. You can get started a couple of weeks earlier by starting your runner beans indoors.

Last Frost Date

In Grinnell the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Grinnell is an average and the actual date of last frost will vary from year to year. Half of the time in Grinnell last frost occurs after April 15 so always be ready to cover your runner beans if you have a late frost.

USDA Zone Info for Grinnell

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 Grinnell

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