We successfully planted a Thuja occidentalis 'Smaragd' hedge of 15 trees last year. All of the trees survived the spring, summer and winter and all of them seem healthy with new growth this spring. In the process of furthering the hedge with another row of cedars, I went around to all of the established trees and fertilized and cleaned up a few branches. One of the trees that I had planted on the sides of the front porch head a strange black (what I thought was signing by fire at first) growth going up only the front side of the tree. It is the only tree that has this growth on it. I have no explanation for it and no information on hand that relates to this. Does anyone out there have any suggestions as to what it could be? I don't want to lose my tree and I most certainly do not want it to spread to any other trees.
You mean like singe as in like by fire scorched looking? I've seen what you are describing, several times. Often, it looks so pitiful, that I just shear off some of the black if green is beneath. Seems I've seen it where one plant was touching another in storage like in the nursery rows. Have no answer as to what it is. Don't think I've seen it spread plant to plant.
