Ornamental evergreens turning brown, bare in patches

Asked June 18, 2018, 4:18 PM EDT

I have three evergreen bushes in a flower bed at the front of my house that have begun looking very sick. They have turned brown in patches and some of the branches on the interior of the trees are bare. I don't see any obvious insect infestation and all other bushes in the flower bed are just fine. Any ideas what might be causing this and what I might be able to do to save them?

New Castle County Delaware spider mites dwarf alberta spruce

2 Responses

Hello,

I believe the problem is due to spider mites and the injury they cause, as the shrubs appear to be dwarf Alberta spruce, and they are very prone to spider mite infestations. Prune out the worst affected. Look for very fine webbing, and very small light colored mites. Spider mites are favored by hot dry and dusty conditions. You want to use a hose spray to wash webbing and dust off the evergreen shrubs. Do not use insecticides, as mites are actually related to spider and are not insects. Insecticides will kill off beneficial insects, and make populations of spider mites increase. You may apply a miticide labeled, check with your garden center. You can use insecticidal soap, sold in home improvement stores or garden center. Another good thing to try would be natural oils for garden use. Peppermint oil and rosemary oil have been shown to control spider mites, used according to the label.

Thank you for contacting Cooperative Extension,
Nancy

Thank you very much for the detailed answer!