Before planting it is a good idea to find your USDA Zone info to determine 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.

It's a good idea to determine when it's the best time to plant four o' clock by referring to the USDA zone info for Charleston.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost.

Since four o' clock are not cold tolerant you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant four o' clock 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 four o' clock and expect a good harvest is probably September. Any later than that and your four o' clock may not have a chance to fully mature. Starting your four o' clock indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Charleston. It might get as low as 20°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Charleston and it is different every year. Since half of the time in Charleston it frosts late in the year after February 15 be ready to cover your four o' clock if you have a late frost.

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.