It all looks good Jelinda, even what you put around the semp. You can even tuck the gravel up under the semp leaves to keep the off the soil. The gravel eventually does mix into the soil, I feel that is a good thing for these types of plants, it just helps with moving water away from the crown of the semps.
Most sedum can handle more water so it's not quite as crucial having the gravel.
The gravel will help to keep the soil cooler and retain moisture in your hot Georgia summers. Just be sure you don't give the semps to much water during the hot weather, you could steam cook them.
