Knowledgebase
T4ree disease #879390
Asked July 30, 2024, 10:51 AM EDT
Todd County Minnesota
Expert Response
That apppears to be a rust but Hawthorne are susceptible to many diseases and this has been a hot wet stressful year.
https://extension.psu.edu/hawthorn-diseases
I checked a number of Long Prairie tree services to find an ISA certified arborist to identify this disease. The websites were incomplete on this matter.
I suggest that you reach out to the Todd County Extension Division for diagnostic help. https://extension.umn.edu/local/todd#gardening-resources-2579162 so that proper treatment can be considered.