We have a 50 year old silver maple that has just begun to show signs that may...

Asked July 7, 2014, 11:51 AM EDT

We have a 50 year old silver maple that has just begun to show signs that may be (?) iron chlorosis. I don't understand why the soil would suddenly become inhospitable to this tree, so I am wondering whether you believe this is the proper diagnosis. If so, I see they are some treatments that the tree professionals can do (injections and such). When is the best time of year to do these? What would you suggest as the preferred treatment for a 28" diameter tree?

Hennepin County Minnesota maple trees tree problem

2 Responses

Thank you for the question. It's hard to tell from the photo just what is wrong with your tree but you can start with this publication from the University of Minnesota on iron and manganese deficiency in trees http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/iron-chlorosis/. Iron and manganese are more readily available to woody plants when the soil pH is between 5.0-6.5. Levels much above this make it hard for the tree to uptake these essential elements. Why a 50 year old tree is struggling now could be due to other factors that make it difficult for it to absorb these minerals. Compacted soil from construction projects, mechanical injury to or diseases to roots, clay soil, excess watering leading to saturated soils ( especially important to consider in our wet spring) all impede absorption. Please read and follow the advice of the article above. You will need to submit a soil test to check your soil pH and iron/manganese levels, and possibly a tissue sample to see just what the tree is deficient in. I would suggest a certified arborist to help with diagnosis and treatment of such an old tree that was apparently healthy in previous years.

Thank you for the prompt response. We will get our soil tested and consult an arborist. Jeff