Good Evening,
Lengthy periods of rain this past May provided conditions for apple scab spores to develop. Scab-infected leaves from the previous season, left on the ground around the tree are the source of fungal spores that can infect the crabapple the next spring. Spores from these old leaves are carried on air currents to new developing leaves. This primary infection produces olive colored spots on leaves.  Apple scab is managed primarily through the application of fungicides from green tip through midsummer. The destruction of leaf litter in the fall by flail mowing or through the application of chemicals that hasten leaf litter degrading, such as urea, helps reduce primary inoculum. The severity of infection depends on a variety's inherent resistance.  You can send in a sample to get a firm diagnosis. Home | MSU Soil Test  You could also have an arborist come out and give you an assessment.  Find an Arborist (treesaregood.org)
References
Why is my crabapple tree losing leaves? - MSU Extension
Crabapple Diseases (psu.edu)
Apple scab - Integrated Pest Management (msu.edu)

I hope this helps.  Thanks for using our service.

Thank you so much. I have scheduled an arborist to take a look tomorrow 

Karrie Doering



Good Morning,
If you don't mind can you let me know what the arborists finds?  
Thanks so much.