Knowledgebase
Burr Oak Question #803684
Asked July 29, 2022, 4:53 PM EDT
Ingham County Michigan
Expert Response
Hello James
This appears to be drought stress. I would wait until late next spring to see which branches show signs of budding out. Then, prune out dead branches and dead branch tips.
What you can do now is keep the tree watered during dry times. Use a soaker hose to slowly give the tree water, so that soil is moist at least 8-10 inches down after you water it. Dig a small hole that deep down after watering to check, noting the time you watered, so you can correctly judge how long this takes. ( Lawn sprinklers are enough to water grass, but not trees).
What also helps is to remove all grass and other plants in a circle ( or a square if you prefer) around the tree. For this tree do this at least 3 feet out or to the farthest reaching branch tip. Then, mulch the bare soil with 2-4 inches deep of chipped or shredded wood mulch. Do not pile any mulch against the trunk of the tree, leave a g” donut hole” of several inches. Maintain this area by hand weeding, so as not to wound the tree with mowers or weed whips.
Here are references for you on tree care that shows proper mulching on page 11, watering on page 13. The second link is a pruning guide.
https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5368392.pdf
The light yellow leaves could be due to the drought stress, or may be a soil pH issue. You can test the soil and if the soil pH is above 7.0 consider treating the tree for iron chlorosis. https://www.canr.msu.edu/uploads/236/21432/Soil_Test.pdfHowever do not treat the tree before it has received adequate water for at least 4 weeks. Details here
https://planttalk.colostate.edu/topics/weeds-cultural-problems/2121-iron-chlorosis-trees/