Fall Tomatoes in Charleston, SC
 

Is it too late to plant tomatoes for a Fall Harvest in Charleston, SC

No, now is a good time to get them in the ground. Boone Hall Plantation has a huge Fall crop of tomatoes (unless a hurricane hits) and I have picked tomatoes there until mid December if conditions are favorable.
I often had a small Spring/Fall garden for many years in Mount Pleasant until I relocated to the NC mountains during the warmer mos.