Is this apple tree treatable? What’s killing it? - Ask Extension
Hi, I have a pair of common apple trees. They have consistently produces small apples every year. However, one tree started to show signs of distress ...
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Is this apple tree treatable? What’s killing it? #863377
Asked April 04, 2024, 5:43 PM EDT
Hi, I have a pair of common apple trees. They have consistently produces small apples every year. However, one tree started to show signs of distress last year. I noticed a sort of mushroom going on it at the end of the season and when I went to inspect it this year I found the bark is coming off and under neath and around the areas of the fungus are a sort of bug that has clearly burrowed in. I am curious if they were drawn by the fungus. But my real question is what is it and can the tree be saved or are we better off removing it? Please attached pics.
Boulder County Colorado
Expert Response
Founds these on the tree
Founds these on the tree
Dug this out? Borer?
Hi Erin,
I'm sorry to hear about your apple tree's troubles! From the pictures you sent, it seems like the insect and the resulting damage could be from an apple tree borer. Below is a link with more information about that particular insect. If you want a confirmed ID I would recommend either sending more pictures or, if you can capture one, feel free to bring a specimen into the extension office.
https://agsci.colostate.edu/agbio/ipm-pests/flatheaded-appletree-borer/
The fungus you sent is a bit hard to diagnose. Below are a few resources about common apple tree funguses and pests that might help with identification.
https://extension.colostate.edu/topic-areas/yard-garden/cytospora-canker-2-937/
https://extension.usu.edu/pests/research/backyard-apple-pests
Pest and disease problems often happen when a tree is stressed, particularly from drought. Trees can become stressed over winter because they don't receive enough precipitation in this area and supplemental irrigation can help.
Regarding how to proceed, it's up to you whether you want to intervene with the tree's ongoing issues. Given the level of damage in your photos, I would recommend getting an arborist involved if you want to keep the tree. Alternatively, our tree team can come out and make a site visit to properly diagnose the team. Let us know if you're interested in that and we can send along more information.
Please let us know if you have any other questions!
Best wishes,
Boulder County Extension Master Gardeners
I'm sorry to hear about your apple tree's troubles! From the pictures you sent, it seems like the insect and the resulting damage could be from an apple tree borer. Below is a link with more information about that particular insect. If you want a confirmed ID I would recommend either sending more pictures or, if you can capture one, feel free to bring a specimen into the extension office.
https://agsci.colostate.edu/agbio/ipm-pests/flatheaded-appletree-borer/
The fungus you sent is a bit hard to diagnose. Below are a few resources about common apple tree funguses and pests that might help with identification.
https://extension.colostate.edu/topic-areas/yard-garden/cytospora-canker-2-937/
https://extension.usu.edu/pests/research/backyard-apple-pests
Pest and disease problems often happen when a tree is stressed, particularly from drought. Trees can become stressed over winter because they don't receive enough precipitation in this area and supplemental irrigation can help.
Regarding how to proceed, it's up to you whether you want to intervene with the tree's ongoing issues. Given the level of damage in your photos, I would recommend getting an arborist involved if you want to keep the tree. Alternatively, our tree team can come out and make a site visit to properly diagnose the team. Let us know if you're interested in that and we can send along more information.
Please let us know if you have any other questions!
Best wishes,
Boulder County Extension Master Gardeners
