Why does my limelight hydrangea have dying branches?

It is very strange that a mature plant suddenly has dying branches with no evidence of insects or disease. Retired MSU Horticulture Specialist Dr. Lelia Kelly wonders if there has been a change with the soil or drainage around the plant. This can cause root rot or other problems. Retired UT Extension Agent Mike Dennison also thinks there may have been digging in the area that damaged the roots.
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Related Videos:
Common Hydrangeas
Why does my hydrangea have brown dark spots all over?

​Related Resources:
Hydrangea Diseases
A Tennessee Landscape Contractor’s Guide to Hydrangeas