Knowledgebase
Discoloration of tree trunk #836114
Asked June 17, 2023, 12:12 PM EDT
I noticed this dark discoloration of my Lance leaf cottonwood near a branch that broke during a heavy spring storm. Should I be worried and have someone take a look? We've had A LOT of heavy rain this year so I thought it may just be getting over saturated in that area, but I wanted to double check. We love this tree
El Paso County Colorado
Expert Response
Hello,
I apologize for the delay in responding to your inquiry. It is difficult to confirm from photos alone, but it appears that your tree could have bacterial wetwood. There are a number of pathogens, both bacterial and fungal that can cause similar cankers in wounded areas in cottonwoods or other Populus species.
Here is a helpful fact sheet with more information. https://extension.colostate.edu/topic-areas/yard-garden/bacterial-wetwood-2-910/
You may want to contact a local ISA certified arborist to have them take a look and recommend next steps. I will attach a list of local arborists with that certification.
Please reach out again if we can provide any additional information.
Thank you,
Allisa Linfield
Horticulture Program Coordinator
CSU Extension El Paso County
