Q.Rhododendron leaves turning red
I have 6 small rhododendron bushes, of which 4 have developed red leaves which are dry. All plants are in the same area and have similar amounts of mulch over proper compost. All of the plants flowered beautifully this last season but I am worried that the affected bushes will not survive the winter into next season. The remaining growth is looking normal and healthy. Is there anything I can do to help these plants? Thank you.
Some varieties of Rhododendrons, especially those with darker red or purple-red flowers will display some leaves turning red as part of their aging process.
Dry conditions could also make leaves turn yellow and red.
There could also be some diseases or pest damage that could appear as red spots or edges of the leaves turning color.
The links below will help you with more information.