Can you tell me what is wrong with my spruce trees?

Asked April 17, 2017, 2:31 PM EDT

It appears my spruce trees have a disease. My husband was told they need fertilizer, but I think they are diseased. From your site I think we should treat with Chlorothalonil. Please review the photos and let me know. I think they may have rhizosphaera kalkhoffii or lirula needle blight. I can be reached at 612-673-5042.

Sherburne County Minnesota diagnosis of plant problems spruce trees horticulture

3 Responses

The tree in the photo is diseased and we think you have diagnosed the cause correctly. However, the disease is so advanced that no control is recommended. It might live for a few more years but it is unsightly and should probably be removed.

Bob, we have more than a dozen trees in our yard with various stages of needle loss. How do we know which ones to treat and which ones to let die? We are trimming up the lower branches for more air circulation and so they look better. It may have started when I put a hosta garden under three trees which formed a triangle and let the sprinkler on which hit the trees and caused excess moisture. The other trees are scattered throughout our yard covering at least three acres. They don't all look this bad. Where do we get the treatment chemical? How do we apply it?

Chlorothalonil is available in various formulations at most full service garden centers, farm stores and hardware stores.

If the trees are large, it may be difficult to apply the chemicals properly without special equipment. Foresters and certified arborists are qualified to assess the trees' condition onsite and determine which, if any, might benefit from treatment. And if controls are needed, they are also equipped to apply them.

The following information may be useful If you decide to hire an arborist:

How to hire a professional arborist to help care for your landscape trees
http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/how-to-hire-a-professional-arborist/