Rhododendrons: Rhododendron pests

This was received via email:

My rhododendrons which I planted last spring have some holes on the edges of the leaves. I would like to know how to get rid of these pests as I lost one plant and I'm not sure if it would be slugs or not that feed on them. I would appreciate hearing from you. Thanks.

 

it may be slug damage, more likely to be damage from weevils. Nematodes applied to the surrounding soil in the early spring can be beneficial to eradicate or control them.

 

rhodo black powder on leaves

How about black powder on the underneath of a old (30yrs) pink rhodo? The flowers are great but the leaves with lots of the black powder turn yellow and brown and blotchy and fall off. since taking ownership I have pruned, not hard, fed with rhodo food, and picked up all leaf debris as often as possible. Is there anything I can spray that won't hurt the environ?

 

black powder could be remnants of sooty mold, a byproduct of insect droppings, sometimes safers soap and a good spray with water can remove some of the sooty mold but it generally takes rain and time to go away on its own.