Shrub Leaf Disease?

Asked June 4, 2018, 2:14 PM EDT

Hi, I have noticed two types of “issues” with the leaves on a couple of shrubs in my yard. One is a white coloration and decay of the leaves affected and the other is a dark coloration that does not seem to cause as much decay/damange to the leaf as the white one. Could you help me identify what are these and what I should do? Thanks!

Washington County Oregon

1 Response

Your rhododendron was sunburned last year. The dark spots are damaged and dead whereas the white spots are also dead but received more intense damage.

You can remove any leaves that you don’t like to look at.

But more important will be to deep water the rhododendron at least once every 2 to 3 weeks during the dry months. Each time, make certain the root zone is moist to 8 inches deep.

And during a heat wave, consider rigging temporary shade at least 18 inches above the shrub.