Staghorn Sumacs are dying
I have a large grove of staghorn sumacs on the border of my backyard. There must be about 20-30 treees, most of which are mature and about 20 feet tall. For some reason, they are all dying. It started with just one, the leaves turned yellow and red, the branches wilted, then it died. And now all the others are slowly dying. Even a sumac tree about 30 feet from the main grove is starting to show the yellowing leaves and wilt.
I am heartbroken and very worried that all the sumac trees are going to die. No more songbirds in the winter! No more beautiful palm effect in summer! I have searched the web extensively and cannot find any reason why this is happening.
The only thing to note is that I did plant a perennial garden right in front of the grove this spring. I tilled the area and removed a large number of staghorn roots and suckers. Did I cause some sort of root rot or disease by cutting the roots? I hope someone can help me. Thanks!