Chlorosis in oak tree? - Ask Extension
Hi Expert -- My (fairly sizeable) oak tree appeared chlorotic last year, so I had it injected with nutrients, in particular, iron. It is considerabl...
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Chlorosis in oak tree? #149417
Asked August 26, 2013, 6:04 PM EDT
Hi Expert --
My (fairly sizeable) oak tree appeared chlorotic last year, so I had it injected with nutrients, in particular, iron. It is considerably better this year, with fewer chlorotic branches, but some of the leaves are now developing brown areas, as in the picture. It is a lower branch, facing due south, but you can see in the picture that the upper leaves are nice and green. The arborist inoculated the tree again today but recommended that I check with the Extension about the brown areas - are they likely the result of severe chlorosis? If so, should I spray the now-chlorotic leaves with iron-containing fertilizer in the spring, or should I have the 3 or 4 chlorotic branches amputated?
Many thanks!
Matt
My (fairly sizeable) oak tree appeared chlorotic last year, so I had it injected with nutrients, in particular, iron. It is considerably better this year, with fewer chlorotic branches, but some of the leaves are now developing brown areas, as in the picture. It is a lower branch, facing due south, but you can see in the picture that the upper leaves are nice and green. The arborist inoculated the tree again today but recommended that I check with the Extension about the brown areas - are they likely the result of severe chlorosis? If so, should I spray the now-chlorotic leaves with iron-containing fertilizer in the spring, or should I have the 3 or 4 chlorotic branches amputated?
Many thanks!
Matt
County
Expert Response
This looks like iron chlorosis scorching. Iron chlorosis can affect the entire plant or just a few branches. Untreated it can lead to scorching (as appears to be the case with these branches), stunted growth, premature leaf drop and die back. There are also many causes such as high soil PH, over watering, soil compaction etc. I have included some links to articles that addresses these very issues that will hopefully be useful. The first is brief and the second contains more detail if you are interested in finding out more.http://www.ext.colostate.edu/ptlk/2121.htmlhttp://www.cmg.colostate.edu/gardennotes/223.pdfSpraying may be of use, but looking for conditions that may be contributing (as outlined in both links) will have the longest lasting effects.To be certain, you can bring in a sample to the Extension Office to get a positive diagnosis of the problem. The sample would ideally include a branch that shows both healthy and unhealthy leaves.
Please let us know if you have any further questions.
Sandra
Please let us know if you have any further questions.
Sandra
