My panicle hydrangea has developed some sort of white "issue." I'm only seeing it at the very top - the tallest branch in the center of the plant - currently.
What is this, and how should I address the problem? Thanks.
Welcome to NGA. Those may be borer insects drilling holes to store eggs inside and producing frass down below. Cut the affected area well back to live, healthy wood with no eggs/larvae and spray Bayer's/Bioadvanced Tree and Shrub Insecticide for borer insects. Be sure to follow the label directions.
Further research led me to believe it's Plant Hoppers ... the white cottony part being the young nymphs and the larger pale green blobs in the photo being more mature adults. Planthoppers are not considered harmful pests that require treatment.
I found it was easily & completely removed from the plant with one blast from my garden hose.
But it could be a cottony scale insect or a borer. So I will monitor the situation and perhaps spray with insecticide soap, hort oil, or your suggested insecticide should it seem necessary. Thanks again.
