Crabapple—apple scab

Asked March 12, 2020, 7:01 PM EDT

I have three mature crabapples that develop apple scab each year. I have them professionally sprayed at the beginning of the season when the leaves are just sprouting but was hoping you could offer suggestions for an at home product I could apply in subsequent applications. Any tips you could offer would be greatly appreciated. They trees are healthy otherwise. Thank you

Oakland County Michigan

1 Response

Hello,

Unfortunately no, there is nothing new in treatment options. Our recommendations for spraying we gave you before haven’t been changed.

If your trees are small, say 12 feet tall or under, you can purchase a sprayer, chemicals, and protective gear for yourself, and do the job yourself. You would be limited to “homeowner” grade chemicals.

Professionals have a license and training to use a wider selection of chemicals and have sprayers that are powerful enough to cover large trees.

So, follow the directions given here earlier- see

https://ask.extension.org/expert/questions/444722

If you decide to proceed yourself, here is a booklet on how to choose a sprayer, how to spray, what fungicides are available, and what each stage of bud/leaf development looks like. While this is for fruit production, you can use the fungicide recommendations for apple to control scab on your crabapples.


https://www.extension.purdue.edu/extmedia/id/id-146-w.pdf


A shorter article is here- see the fungicides section:

https://extension.umn.edu/plant-diseases/apple-scab#fungicides-1165363

I hope these articles help you decide whether the investment in equipment and chemicals is something you want to pursue. Thank you for using our service.