Knowledgebase
Help for Diseased or Dying Snow Crab Apple Tree #844701
Asked August 08, 2023, 11:04 AM EDT
My snow crab apple tree is 33 years old. The past five years or more the spring blooms are not as much as they used to be and fall off quicker. The leaves are turning yellow and have brown/black spots on them, and fall off much earlier than prior to fall like they used to do. Some of the branches appear to have moss on them. The bark is peeling looking but a nursery told me that was the nature of the tree. There was some ground perennials under the tree but a couple of hostas decided they liked to spread out and grew around the tree. I don't know if the tree is nearing its lifespan, has an insect problem, hostas taking up too much water or something else. I haven't fertilized the tree. I always have birds in this tree and a bird house that houses a nest so anything I use I would prefer to be safe for wildlife. I have attached photos.
Thank you!
Cynthia Wood
Wayne County Michigan
Expert Response
Based on what I see in your images, it appears you have apple scab (looking at the leaves). Apple scab is the major problem. Peeling bark is not always cause for concern. For instance, the crabapple variety 'Brandywine' has beautiful exfoliating bark that is natural to the tree and one of its nicest features. Most crabapples develop a 'mottled' looking bark as they mature. Common pests that can affect crabapple trees include Aphids, Japanese Beetles & Mites - I can't really tell with the images provided
PLEASE get a confirmed diagnosis from the MSU Diagnostic Plant & Pest Lab - Please email all your digital images prior to bringing or sending physical samples. The images can be sent to <personal data hidden>.
MAKE SURE IN THAT E-MAIL YOU INCLUDE YOUR NAME, ADDRESS, AND PHONE NUMBER!!
Be prepared. The lab may ask for more images - THE LAB WILL LET YOU KNOW IF A SAMPLE NEEDS TO BE SENT - There is a $20-25 dollar fee (if they need a sample sent).
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Also, please read the articles below: THANK YOU!!
Apple Scab - MSU at this link: https://www.canr.msu.edu/ipm/uploads/files/WoodyLandscape_PDFs/AppleScab.pdf
Crabapple Diseases - Informational table showing disease name, symptoms, pathogen/cause, and management of Crabapple diseases. Penn State Extension at this link: https://extension.psu.edu/crabapple-diseases
Why is my crabapple tree losing leaves? - Bob Bricault, Michigan State University Extension - September 05, 2017 - Apple scab fungus on crabapples has left trees with few leaves, but the tree is not dying. At this link: https://www.canr.msu.edu/news/why_is_my_crabapple_tree_losing_leaves
Apple Scab Disease - University of Maryland at this link: https://extension.umd.edu/resource/apple-scab-disease
I hope this helps!
Thank you for responding so quickly and for all of this good information! I will be sending my photos to the lab today. You mentioned that I should clear the area around the tree and rake up the dead leaves. The hostas decided to grow there so it will be difficult to rake with them there. There's about 2 ft of space around the perimeter of the trunk where the hostas are growing. Is that enough space so the tree can breathe or should I thin back some of the hostas? Also how can I rake up the dead leaves with the hostas there? Many of the Dead leaves are sitting on top of the hosta leaves or have fallen through.
Thank you!
-----Original Message-----
From: Ask Extension <<personal data hidden>>
Sent: Aug 8, 2023 6:20 PM
To: Cynthia Wood <<personal data hidden>>
Subject: Re: Help for Diseased or Dying Snow Crab Apple Tree (#0114627)
Yes, it would be a great idea to thin out the hostas. It would give the crab apple tree some breathing room. You should cut back the hosta foliage in the fall. Then you can use a blower to remove the crabapple leaves and cut up hosta foliage rather than raking. The whole idea is to sanitize the area from the dead crab apple leaves.
I hope this helps!
I can do that. Thank you!
-Original Message-----
From: Ask Extension <<personal data hidden>>
Sent: Aug 9, 2023 4:58 AM
To: Cynthia Wood <<personal data hidden>>
Subject: Re: Help for Diseased or Dying Snow Crab Apple Tree (#0114627)
