The leaves on my dwarf rhododendron have little white spots.
What is the cause and how do I treat it?
Thank you for contacting Toronto Master Gardeners with your enquiry about the small white spots on the leaves of your dwarf rhododendron (Rhododendron).
It is difficult to determine from the photo if the spots are raised or integral with the leaf surface. We wonder if the spots easily wipe off with your finger, and if there is stickiness on the leaf surface or on the reverse, or any webbing or marking on the under surface of the leaf.
Our search has not revealed a similar problem. This extensive picture collection does not show a leaf problem similar to yours https://www.google.com/search?q=rhododendron+diseases+pictures&sa=X&biw=1278&bih=882&tbm=isch&source=iu&ictx=1&fir=YQY8eP6XE_GxGM%253A%252CsNH2K1adxxXWcM%252C_&vet=1&usg=AI4_-kToSFvD2mH5DwXin_tgJTaEimQ4Qg&ved=2ahUKEwi7hbGPvIzhAhXH5IMKHYL2BUEQ9QEwCHoECAEQFA#imgrc=4YRQwkgkvpJG8M:&vet=1
A further identification of Rhododendron problems is well covered in this document https://www.gardeningknowhow.com/ornamental/shrubs/rhododendron/issues-with-rhododendrons.htm
We suggest that you continue to monitor your little plant, checking the underside of the leaves affected and also to note any unusual characteristics of the plant which may help to identify the source of the little white spots.
The plant looks quite healthy at present, with fat flower buds. We wish you a good blooming season for your wee rhodo.