The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of determining when it's the best time to plant regal geranium is to use the USDA zone info for Charleston.

Planting Calendar for Regal Geranium

Frost tolerance for regal geranium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Regal Geranium are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant regal geranium 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 regal geranium and expect a good harvest is probably August. If you wait any later than that and your regal geranium may not have a chance to fully mature. You can get started a little bit earlier by starting your regal geranium indoors.

Last Frost Date

The average date of last frost is April 15 in Charleston. You should expect an average low temperature of -5°F in the coldest months of winter.

It's important to remember that USDA zone info for Charleston may not be accurate from year to year and 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 just be sure to be ready to protect your regal geranium in the event of a surprise late frost.

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.