effect of too much nitrogen on Skyline Honey Locust

Asked June 20, 2016, 1:54 PM EDT

For the second year in a row our 4 year old honey locust has excessive leaf growth. So much so that the trunk and major limbs can't support it. We had an arborist trim the tree last summer to remove much of that growth. He said that the tree was getting too much nitrogen. He told us to keep any lawn fertilizer outside an 8 foot radius of the tree. The same thing happened this year. The tree is bent over from the extra weight. We are concerned that it will never recover. He is coming back to retrim the tree and to treat the soil for excess nitrogen. We have been told to stop all lawn fertilization. Is excessive soil nitrogen the likely cause of our problem, or could it be something else? Thanks for your response. Paul Marinac

Ramsey County Minnesota

1 Response

I don't know how often you are fertilizing your lawn or what type of fertilizer you use. It is true that trees will absorb fertilizer from the lawn as their roots are wide spread. Try going back to just one application of fertilizer in the fall. Use a fertilizer that is low in nitrogen (the first number) or just skip it altogether for the rest of the year.