mature black walnut tree

Asked July 20, 2016, 10:20 AM EDT

My black walnut tree is dropping individual yellow leaves. Why is this? When I look up at the tree from underneath, I have a hard time seeing yellow leaves but it seems to "rain" individual yellow leaves when the wind blows. This year seems to be an especially low black walnut year too. Probably not connected to leaf dropping though. Thank you.

Hennepin County Minnesota tree health black walnut tree

1 Response

Thank you for the question. Yellow leaves dropping prematurely is a fairly non-specific finding. We can't know if there is disease, insect, or cultural problems affecting your tree so you will have to inspect your tree thoroughly. Check branches, trunk, tops and bottoms of leaves to try to get more clues. If the tree is valuable in your landscape we do suggest having a certified arborist take a look because proper diagnosis of tree problems is very difficult through electronic communication. Here is our publication on what to look for when hiring a properly certified arborist: http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/how-to-hire-a-professional-arborist/

Please check out our on-line self diagnostic program http://www.extension.umn.edu/garden/diagnose/plant/.

Read about walnut anthracnose which can cause premature falling and yellowing of leaves http://msue.anr.msu.edu/news/walnut_anthracnose_is_putting_an_early_end_to_many_leaves

Thank you for contacting Extension.