Smoke Tree Disease - Ask Extension
Hi, Individual limbs on my smoke tree keep dying off. I'm not sure what could be causing it.
Facts about the tree
1) planted about 5 years ago
2) i...
Knowledgebase
Smoke Tree Disease #880039
Asked August 03, 2024, 2:24 PM EDT
Hi, Individual limbs on my smoke tree keep dying off. I'm not sure what could be causing it.
Facts about the tree
1) planted about 5 years ago
2) it didn't start having issues until last year when the first branch died off
3) it's planted on the North side of the house
Licking County Ohio
Expert Response
From your pictures and description, I think the most likely culprit is a fungus called verticulum wilt. This lives in the soil, and Smoke trees seem to be particularly susceptible to it. It causes disruption of the vascular bundles in the tree's circulatory system
and eventually blocks water movement in a branch that will lead to wilting and eventually death of that individual branch. There is no cure for this; eventually an infected plant will die. Minimizing stress with proper watering, fertilization, etc may prolong the life of the plant. Diagnostic testing can be done at the C. Wayne Ellett Plant and Pest diagnostic laboratory. (ppdc.osu.edu). Contact them for information on sample submission.
Smoke trees are said to be hardy down to growing zone 5, but individual types may prefer warmer areas. Licking County seems to be zone 6a (warmer than zone 5), but microclimates may vary.
The link below should let you zero in on your exact area.
The placement of your tree on the north side of the house may subject it to cold winter winds, which would stress the tree. Poorly draining soil may also stress the tree and make it more susceptible to disease. Do you know your soil type? In general, clay type soils drain more poorly than sandy or loamy soils. While Smoke trees are relatively pest and disease-free, the verticulum wilt is one disease they are prone to. Since the fungus is in the soil, the best "treatment" is to grow plants that are resistant to it. Pruning affected branches and removing (not composting) them may prolong the life of the tree.
The three links below all describe the care and management of Smoke trees, mentioning their susceptibility to verticulum wilt.
https://plants.ces.ncsu.edu/plants/cotinus-coggygria-royal-purple/
https://plants.ces.ncsu.edu/plants/cotinus-obovatus/
https://plants.sc.egov.usda.gov/home/plantProfile?symbol=COOB2
Check out the links below, along with the pictures that are in the articles. There is a home "test" you can do, looking for a specific type of damage in the wood of a tree, that is highly suggestive of verticulum wilt. If these descriptions match what you have observed in your tree, laboratory testing may not be needed to get a presumptive diagnosis.
Good description of verticulum wilt with pictures; smoke tree is mentioned as particularly susceptible.
https://hort.extension.wisc.edu/articles/verticillium-wilt-of-trees-and-shrubs/
And another description with pictures
https://purdueplantdoctor.com/factsheet/tree-89
Please let me know if the pictures and descriptions match what you are seeing; if you have further information I would be happy to re-visit the question. Thank you for asking Extension about your tree.
and eventually blocks water movement in a branch that will lead to wilting and eventually death of that individual branch. There is no cure for this; eventually an infected plant will die. Minimizing stress with proper watering, fertilization, etc may prolong the life of the plant. Diagnostic testing can be done at the C. Wayne Ellett Plant and Pest diagnostic laboratory. (ppdc.osu.edu). Contact them for information on sample submission.
Smoke trees are said to be hardy down to growing zone 5, but individual types may prefer warmer areas. Licking County seems to be zone 6a (warmer than zone 5), but microclimates may vary.
The link below should let you zero in on your exact area.
Ohio Interactive USDA Plant Hardiness Zone Map - Plantmaps
www.plantmaps.com/interactive-ohio-usda-plant...The placement of your tree on the north side of the house may subject it to cold winter winds, which would stress the tree. Poorly draining soil may also stress the tree and make it more susceptible to disease. Do you know your soil type? In general, clay type soils drain more poorly than sandy or loamy soils. While Smoke trees are relatively pest and disease-free, the verticulum wilt is one disease they are prone to. Since the fungus is in the soil, the best "treatment" is to grow plants that are resistant to it. Pruning affected branches and removing (not composting) them may prolong the life of the tree.
The three links below all describe the care and management of Smoke trees, mentioning their susceptibility to verticulum wilt.
https://plants.ces.ncsu.edu/plants/cotinus-coggygria-royal-purple/
https://plants.ces.ncsu.edu/plants/cotinus-obovatus/
https://plants.sc.egov.usda.gov/home/plantProfile?symbol=COOB2
Check out the links below, along with the pictures that are in the articles. There is a home "test" you can do, looking for a specific type of damage in the wood of a tree, that is highly suggestive of verticulum wilt. If these descriptions match what you have observed in your tree, laboratory testing may not be needed to get a presumptive diagnosis.
Good description of verticulum wilt with pictures; smoke tree is mentioned as particularly susceptible.
https://hort.extension.wisc.edu/articles/verticillium-wilt-of-trees-and-shrubs/
And another description with pictures
https://purdueplantdoctor.com/factsheet/tree-89
Please let me know if the pictures and descriptions match what you are seeing; if you have further information I would be happy to re-visit the question. Thank you for asking Extension about your tree.
