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

A common way of figuring out when it's the best time to plant runner beans is to examine the USDA zone info for Portsmouth.

Planting Calendar for Runner beans

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

You should not plant runner beans until after the last frost has passed because they require warm weather.

The earliest that you can plant runner beans in Portsmouth 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. Any later than that and your runner beans may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your runner beans indoors.

Last Frost Date

In Portsmouth the average date of last frost happens on April 15. You can expect an average low temperature of -5°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 Portsmouth and it will vary from year to year. Half of the time in Portsmouth you get surprised by a frost after April 15 so just be sure to be ready to cover your runner beans if you have a surprise late frost.

USDA Zone Info for Portsmouth

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 Portsmouth

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