Q: The backs of my fern leaves are covered in spots, every plant is like this and they seem weak. We know they grow well here in Savannah because there are fabulous, huge ones in the squares. What could this be, and how can I get rid of it?
A: You have a holly fern, Cyrtomium falcatum. I’m not sure why they haven’t prospered. They should be right at home in Savannah if watered when it gets dry.
The spots on the backs of leaves are sori: the structures that contain and disperse fern spores. They are not harmful in the least.
Try fertilizing with diluted Miracle-Gro or fish emulsion. This should get them growing and recovering from any weakness.