I live in Toronto (Bathrust and Wilson) -zone 6
I am wondering if you can give me some advice about this rhododendron.
There are 2 planted right near each other, they are healthy plants and about 5 years old.
As far as I know the drainage is good, and similar for both of them. They get plenty of water. I don’t know what the soil type would be called but it has good top soil and more was added this year in the spring.
On one plant around each bud, the leaf cluster seems discoloured/yellowing and a bit shrivelled.
There is a second rhododendron plant near this one that is green and happy.
Suggestions would be appreciated.
Perhaps it’s a mineral deficiency, if so which one, and what is best to use to to treat.
Yellowing and distorted terminal leaf buds can be a symptom of an infestation of Longtailed Mealybug. There is an excellent description of their damage and management, using horticultural oils, on the University of Maryland website here. Other rhodo problems are described there also.
Good luck with your rhodos!