Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant string beans in Waterloo should be estimated by looking at the USDA zone info.

Planting Calendar for String beans

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

Since string beans are not cold tolerant it's necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant string beans in Waterloo 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 grow to maturity. Starting your string beans indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Waterloo may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Waterloo last frost occurs after April 15 be ready to cover your string beans in the event of one of those late frosts.

USDA Zone Info for Waterloo

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 Waterloo

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