Large Magnolia Tree Suddenly Looking Thin With Light Green On Bark

Question From: Venice, Florida, United States
Q: We have a very large magnolia that is suddenly looking thin. The bark is covered with a substance that is light green and looks like lichen but is smooth to the touch. Any idea what it is and how to treat?

A: It probably is a lichen or moss. The fact that it is looking thin is what would bother me. If it were my tree I would get and onsite inspection from a professional. To find a certified arborist in your area go to and enter your zip code. Best And Happy Yardening, Nancy