I've been losing plants for the last few years with what appears on one branch and eventually takes over and kills the entire plant. At present I have one plant in front yard and one in back yard with the same issue. One is a bush cherry hedge. Armstrong nursery said its from overwatering but these have been on same watering schedules for up to 25 years. any suggestions?
Certified GKH Gardening Expert
I am, also, likely to agree and say it is most likely due to over-watering. Some fungal infections can take years to progress. If they don't get treated, they will remain in the soil for a very long time. The plants should only be watered when they are completely dry down to about 2 inches deep in the soil.
You can correct the problem in the soil by adding wettable sulfur and dolomitic lime to all infected areas. This will help make the soil usable again.