One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when to plant scarlet runner beans is to look at the USDA zone info for Harrisburg.

Planting Calendar for Scarlet Runner Beans

Frost tolerance for scarlet runner beans:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant scarlet runner beans until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant scarlet runner beans in Harrisburg 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. Any later than that and your scarlet runner beans may not have a chance to grow to maturity. You can get started a little bit earlier by starting your scarlet runner beans indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Harrisburg. It might get as low as 5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Harrisburg may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Harrisburg you get surprised by a frost after April 15 be ready to protect your scarlet runner beans in the event of a surprise late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°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 10°F.

Plants to Grow in Harrisburg

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