What is going on with these Pieris?

Asked August 28, 2019, 10:22 AM EDT

I was out of town July 16-Aug 22. When I returned nearly all the leaves on a Pieris had fallen off. Many on the ground were green, some yellow, some brown. There appears to be some new growth along with remaining brown leaves. I am including a before picture from late May and 2 pictures taken this morning. Any help much appreciated. Laura

Montgomery County Maryland

1 Response

We cannot say for sure what is going on. The plants can be susceptible to a root rot and possible borers (rhododendron). The borers can cause wilting of leaves and twig dieback. Prune off the suspected branches (declining) and split them open longitudinally to see if larvae are present. If so, all you can do is prune the branches back to healthy tissue.

We notice that the ferns look healthy nearby. What is the site like? If there is a leak near the pond or poor drainage, the plants can be susceptible to a root rot. All you can do is check the drainage and prune dead wood. Repair the leak or increase the drainage. Scratch the branches with your fingernail and look for green tissue. If you see it, the branch is alive. If you see brown/gray, then it is dead. All you can do is prune.