Hi there, Curious. If I slowly trim back my arborvitae will it resume inner growth. They were next to our deck when we moved in and have been neglected (About 14' X 7 and little inner growth... if any). I think they are at least 20 years old. We have been here 17yrs. I would hate to remove them and start over and lose the bit of privacy they provide. At this point I don't think I have another option. I took out some inner dead branches to allow more light inside last year. There is some (very little) green inside now. One of the tree (the center one) Looks like it has a round spot about 3" where it looks as though it is starting to rot at the base :( Are they a lost cause?...Also, How long do they normally live?