One of the first steps you take when you are getting a good idea your gardening schedule is find your 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 best time to plant scarlet runner beans in Charleston should be determined by looking at the USDA zone info.

Planting Calendar for Scarlet Runner Beans

Frost tolerance for scarlet runner beans:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Scarlet Runner Beans require warm weather which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant scarlet runner beans in Charleston is March. However, you really should wait until April 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 September. Any later than that and your scarlet runner beans may not have a chance to grow to maturity. Starting your scarlet runner beans indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Charleston the average date of last frost happens on February 15. You can expect an average low temperature of 20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Charleston is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Charleston it frosts late in the year after February 15 be ready to cover your scarlet runner beans if you have one of those late frosts.

USDA Zone Info for Charleston

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°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 25°F.

Plants to Grow in Charleston

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