I have a number of Ficus trees planted a few feet apart and topped to about 10 ft to form a hedge accross the rear of my property.

I would like to know what variety of Ficus they are and also get advice on pruning. The trees would grow to 40 or more feet if allowed which may assist in answering the question about the variety.

I live in the desert near Palm Springs and recently a frost burned the top foot or so of the Ficus hedge. I would like to know what is the appropriate treatment and when should it be carried out? Should I prune off the top foot which has burned? Or just remove the leaves? And if so when? Or do nothing?