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

The USDA zone info for Waterloo can be reviewed 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.

You really shouldn't plant scarlet runner beans until after the last frost has passed because they require warm weather.

The earliest that you can plant scarlet runner 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 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 little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Waterloo. You should expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Waterloo is just an average the actual date of last frost changes from year to year. Since half of the time in Waterloo it frosts late in the year after April 15 be ready to protect your scarlet runner beans if you have a late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Waterloo

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