Apple Tree Leaf Drop

Question: For the past 2-3 years our apple trees; edible crabapple, Macintosh, empire and some heirloom varieties, lose their leaves from the bottom up, usually starting in early July, and will be almost leaf-less by the end of summer.  Is this a fungus?  Do you know what causes this and what I can do about it as organically as possible as soon as possible?  We also can lose the fruits that fall prematurely- we like to grow our own organic food so need to figure this out.  Thank you for taking the time to help!

responder: Dan D. (Greene Co)  Replied August 28, 2024, 12:54 PM EDT
response: Karen,     Most likely, the problem you are experiencing is indeed a fungal issue that causes a disease common to apples called Apple Scab. I say most likely because while the symptoms you expressed match the disease progress over time, I cannot see the leaves clearly enough to be absolutely certain.    While there are fungicides, both inorganic and organic, that do slow the annual progression of Apple Scab, they don't cure the disease. The most commonly recommended approach is, over time, to replace existing trees with Apple Scab resistant varieties. Apple Scab does not outright kill the apple trees, but the annual defoliation weakens the trees to the point they eventually die off.    Here is link to a really good fact sheet on Apple Scab from OSU Extension: https://ohioline.osu.edu/factsheet/plpath-fru-23.    I've had a number of apple and crabapple trees over the years and each eventually developed Apple Scab and had to be removed.  It's really hard as in your case where you have some trees that are heirlooms and nothing can replace them.    Thank you for your question and hopefully you will have a good late summer and fall.

responder: The Question Asker Replied October 04, 2024, 10:45 AM EDT
response: I have not heard back Freon anyone regarding my issue with my Apple trees?  Can someone please help??Sent from my iPhone On Aug 26, 2024, at 5:09 PM, Ask Extension wrote:﻿  Dear Karen, Thank you for using Ask Extension. A request for support has been created and a representative will follow-up with you as soon as possible. Questions are usually answered within two business days. You can view this question's progress online. YOUR QUESTION #0152995: Apple Tree Leaf Drop For the past 2-3 years our apple trees; edible crabapple, Macintosh, empire and some heirloom varieties, lose their leaves from the bottom up, usually starting in early July, and will be almost leaf-less by the end of summer. Is this a fungus? Do you know what causes this and what I can do about it as organically as possible as soon as possible? We also can lose the fruits that fall prematurely- we like to grow our own organic food so need to figure this out. Thank you for taking the time to help! Ask Extension offers one-to-one expert answers from Cooperative Extension/University staff and volunteers within participating Land-Grant institutions across the United States. If you wish to provide additional comments or information regarding the issue, please login to your account for a complete archive of your prior questions and answers.  This message for informational purposes only. It is not intended to be a substitute for personalized professional advice. For specific local information, contact your local county Cooperative Extension office or other qualified professionals. eXtension Foundation does not recommend or endorse any specific tests, professional services, products, procedures, opinions, or other information that may be mentioned. Reliance on any information provided by eXtension Foundation, employees, suppliers, member universities, or other third parties through eXtension is solely at the user's own risk. All eXtension content and communication is subject to the Terms of Use which may be revised at any time.

responder: Jennifer Andon  Replied October 04, 2024, 3:22 PM EDT
response: Karen,  Most likely, the problem you are experiencing is indeed a fungal issue that causes a disease common to apples called Apple Scab. I say most likely because while the symptoms you expressed match the disease progress over time, I cannot see the leaves clearly enough to be absolutely certain. While there are fungicides, both inorganic and organic, that do slow the annual progression of Apple Scab, they don't cure the disease. The most commonly recommended approach is, over time, to replace existing trees with Apple Scab resistant varieties. Apple Scab does not outright kill the apple trees, but the annual defoliation weakens the trees to the point they eventually die off. Here is link to a really good fact sheet on Apple Scab from OSU Extension: https://ohioline.osu.edu/factsheet/plpath-fru-23. I've had a number of apple and crabapple trees over the years and each eventually developed Apple Scab and had to be removed. It's really hard as in your case where you have some trees that are heirlooms and nothing can replace them. Thank you for your question and hopefully you will have a good late summer and fall.  Dan