Burr Oak dropping leaves #648204 - Ask Extension

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Burr Oak dropping leaves #648204

Asked June 09, 2020, 10:22 AM EDT

1) Our nice burr oak is dropping leaves . Most are slightly eaten on edges . My guess is scale // ?? Can I spray —- with what?? Thank you !! 2) sorry second question — About 25 year old white pine is ‘’browning ‘’ it’s needles . I don’t see any bugs/ rust ,,etc.. Anything I can do ??

Washington County Minnesota

Expert Response

Thank you for writing.
I am sorry the pictures are just not clear enough.
One possibility center picture is Oak Leaf Gall  https://hortnews.extension.iastate.edu/2010/8-25/oakgalls.html#:~:text=These%20growths%20are%20known%20as,by%20small%20wasps%20or%20midges.
Oak wilt is the worst case scenario.  https://extension.umn.edu/plant-diseases/oak-wilt-minnesota#how-is-the-oak-wilt-fungus-spread%3F-1258961

This pamphlet on Oak Diseases may give you a better idea.  http://www.myminnesotawoods.umn.edu/wp-content/uploads/2015/03/HowToRecognizeCommonDiseasesOaks.pdf 

In any case a large oak is valuable.  Consider calling a qualified arborist.  https://extension.umn.edu/planting-and-growing-guides/how-hire-tree-care-professional
In the case of the pine, I need a close up of the needles and two small branching points. Blister rust would be the most common  https://extension.umn.edu/plant-diseases/white-pine-blister-rust  but Cytospora Canker, commonly thought of as a Colorado spruce disease also affects white pine.  https://extension.umn.edu/plant-diseases/cytospora-canker

Steve Miles Replied June 09, 2020, 10:37 AM EDT
Thank you very much for your response ..  Sorry for  poor pics....  Tree is very healthy — except for recent leaf issues ..  Took some ,,I hope ,, better photos..

not sure what is happening to the nice pine —- bummer 

 Again, Thxs so much for your time and expertise ...
     Jack St. Ores 
     Baytown 
The Question Asker Replied June 09, 2020, 10:44 AM EDT
Thank you very much for your response ..  Sorry for  poor pics....  Tree is very healthy — except for recent leaf issues ..  Took some ,,I hope ,, better photos..

not sure what is happening to the nice pine —- bummer 

 Again, Thxs so much for your time and expertise ...
     Jack St. Ores 
     Baytown 
The Question Asker Replied June 09, 2020, 10:44 AM EDT
Fascinating.
The oak problem appears to be a twig gall--see those bumpy things at the twig just before it gets to the leaf.  http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/other/galls/gouty-horned-and-other-twig-galls.aspx

I can not find anything on management but the literature suggests the tree will survive.  I suggest you call an arborist per info given in my first post.
With regard to the pine--should a picture of the needles and twig branching from 6 inches away.  


Steve Miles Replied June 09, 2020, 12:05 PM EDT
Steve,,
 thanks again...    In another life ,,was deep into biology —- education / work .  So ,  find your support very helpful .. We live in a wonderful  area — 8 acres ,, pond / small lake =   Almost a wildlife preserve . My wife is an officer in local Stillwater garden club —-  they volunteer gardens in area ,, like by the hospital.
    I  understand some type or ‘’oil ‘’ spay in the Fall helps with this gall — will investigate ..Have 7  100+ year old white oaks I need to protect ....
      Be safe
The Question Asker Replied June 09, 2020, 2:15 PM EDT
You as well.
It was peaceful out there today
Steve Miles Replied June 09, 2020, 4:42 PM EDT

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