One of the first steps you take when you are estimating 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.

In Charleston you can figure out when it's a good idea to plant regal geranium by using the USDA zone info.

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 can survive in some cold which means that you can plant them a bit earlier in the year than other frost tender 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. You probably don't want to wait any later than that or else your regal geranium may not have a chance to grow to maturity. If you are starting your regal geranium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Charleston. In the coldest months of winter you can expect an average low temperature of 0°F.

Just be sure to remember that USDA zone info for Charleston is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Charleston last frost occurs after April 15 so just be sure to be ready to cover your regal geranium if you have a surprise late frost.

USDA Zone Info for Charleston

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°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.