The two primary reasons that rhododendron leaves turn brown are cold weather and rhododendron wilt.
34+ Rhododendron Problems Brown Leaves. Symptoms are pale spots on upper leaf surface, with corresponding brown/grey patches underneath Brown spots on hydrangea leaves.
Brown Marks On Rhododendron Leaves Tikorangi The Jury Garden from tikorangi.files.wordpress.com
I have a fairly young rhododendron (at least two years). Rhododendron borer causes wilting of leaves and twig dieback. The soil is acidic, but to what degree i am not sure.
Rhododendron leaves will curl inward and droop. In most cases, the fungus or bacteria does not threaten the life of the plant, but the spots can be unattractive. Learn when to plant rhododendrons based on your climate and how to prune them for the best. Aside from browning leaves, the roots of infected plants are often described as mushy and dark in color.
