Flowering Crab Apple - brown spots - Ask Extension
I noticed the leaves on my flowering crab apple tree thinning and on closer inspection I see brown spots forming on the leaves (see attached picture)....
Knowledgebase
Flowering Crab Apple - brown spots #874889
Asked June 26, 2024, 10:00 PM EDT
I noticed the leaves on my flowering crab apple tree thinning and on closer inspection I see brown spots forming on the leaves (see attached picture). The tree is about 12 or 13 years old and I don’t recall seeing this before. Is this a fungus from the wet spring and early summer that we’ve been experiencing?
Washington County Minnesota
Expert Response
We think you have diagnosed the problem correctly. Conditions this spring have been very conducive to the spread of a fungal disease called apple scab. Even some tree that are resistant and seldom affected are showing symptoms.
Scab often defoliates susceptible ornamental crabapple trees by midsummer. However, trees so affected usually recover, and even bloom normally the following spring. Still, because frequent defoliation weakens trees, control is sometimes needed.
Go here to learn more about scab and how to manage it:
https://extension.umn.edu/plant-diseases/apple-scab#fungicides-to-protect-ornamental-crabapples-from-apple-scab-3652960
Scab often defoliates susceptible ornamental crabapple trees by midsummer. However, trees so affected usually recover, and even bloom normally the following spring. Still, because frequent defoliation weakens trees, control is sometimes needed.
Go here to learn more about scab and how to manage it:
https://extension.umn.edu/plant-diseases/apple-scab#fungicides-to-protect-ornamental-crabapples-from-apple-scab-3652960
