Changing zone guides
I live in Murrells Inlet, SC and for a decade or so have had trouble with any zone 8 plant thriving due to the heat. So now I only buy plants that are zone 9 or 10. With our temps going up, don't you think that the zone guides need to be adjusted?
Horry County South Carolina horticulture
The USDA redid the Plant Hardiness Zone Map in 2012. Her is a link to the new map. http://planthardiness.ars.usda.gov/PHZMWeb/
I think you will find that in the area you are in, you fall in zone 9 on the new map.
I hope this is helpful.