Bottom Of Arborvitaes Have Lost Their Green

Question From: Milwaukee, Wisconsin, United States
Q: I have 18 year old arborviataes they about 12 ft tall. All the green has been lost(about two or three feet) on the bottom of the tree the last two winters. I dont know what to do.

A: Do you have deer in the area? I use Plantskydd on my shrubs. Best And Happy Yardening, Nancy