I used to have a beautiful Hydrangea that had huge deep pink flowers and large leaves, planted in a large pot in my garden. Sadly it has been badly infected with Hydrangea scale. Last year it was affected as well but it recovered. This year the infection is much worse, the sap is going from the leaves which are covered in the white sticky blobs, the stems have darkened and have the white blobs all down them and it seems at the moment I will only have two flowers on the plant. I have sprayed with Resolva Bug Killer but it isn't stopping the infection. Do I persevere or sentence it to death!