Thank you for your question, Dave. The pale green/grey structures are lichens; the green "furry" structure mixed in with it is moss. Moss is a briophytic plant. Before you go destroying either of them, you should know that (1) they are incredibly valuable in the environment; (2) they are not harming your trees and shrubs and (3) they are an indication you have little or no pollution. They help clean the air of toxins, hold moisture near the tree's surface, and important in the habitat of wildlife. More here:  https://s3.wp.wsu.edu/uploads/sites/2073/2014/03/02-24-12_Lichens.pdf

And here is a great article on mosses--explaining why what you have is not Spanish moss:  https://s3.wp.wsu.edu/uploads/sites/2073/2014/03/021414.pdf

Enjoy!