Mildew on spruce trees

Asked September 5, 2019, 10:56 AM EDT

We have a line of spruce (I think) on our property, some of which have a green mildew on the branches. At least 2 trees are dead—from the mildew? I have attached photos of the mildew on branches and one of the dead trees

Grand Isle County Vermont

2 Responses

Hi Grand Isle County Gardener!

Thank you for sending the three photos. Alas: it's difficult to see much in the photographs beyond the dying branches and lichen (on those branches). Lichen does not harm trees directly, but is often a sign that the tree is stressed and weakened from something else.

We'd be happy to diagnose a sample from one of your trees. There's no cost for this service beyond your time and postage (or if you are coming into Burlington, you can also drop off samples directly in our lab in the Jeffords building at UVM).

Instructions for submitting a sample can be found at our web site -- there's a link in the paragraph below. (From the home page, click on "Ask a Master Gardener" and on that page, scroll down to "Submit a Sample." Note that we need a sample of a living branch -- we can't tell from the photos, but perhaps you can see some signs of distress on some of the living branches? (E.g.: white, powdery material, leaf spots or galls/eggs, etc.) The instructions also tell you to try to provide a sample from the roots (in case the problem lurks there).

I hope you can provide a sample.

Thank you for this information. I will try to bring in a sample to UVM.