Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You will be able to determine when it's the best time to plant runner beans by checking out the USDA zone info for Charleston.

Planting Calendar for Runner beans

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

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

The earliest that you can plant runner beans in Charleston 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 grow to maturity. Starting your runner beans indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Charleston the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Charleston and it can change quite a bit from year to year. Since half of the time in Charleston you get surprised by a frost after April 15 be ready to protect your runner beans if you have one of those late frosts.

USDA Zone Info for Charleston

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 Charleston

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