The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 catharanthus in Charleston should be figured out by looking at the USDA zone info.

Planting Calendar for Catharanthus

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

It's a bad idea to plant catharanthus until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant catharanthus 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 catharanthus and expect a good harvest is probably August. If you wait any later than that and your catharanthus may not have a chance to really do well. You can get started a couple of weeks earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Charleston. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Charleston may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Charleston there is a last frost after April 15 so be sure to be ready to protect your catharanthus in the event of a surprise late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 6a.

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

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Charleston

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