Our boxwood have a white mold on the branch’s under the canopy. Also the flower stem of our hosta plants have a similar white mold with white winged insect. Any idea what our disease is have? We have about 100 plants.
Worcester County Maryland
This sounds like you may be referring to planthoppers. This is a sucking insect and the white waxy material is produced by the nymphs.
No control is necessary. However, you can wash it off the stems of your plants with a stream of water. Here is our web page https://extension.umd.edu/hgic/topics/planthoppers-flowers
If this is not what you are noticing, please send us photos of the whole shrub, around the base, and affected foliage so we can see what you are dealing with.