Hydrangea Annabelle Heartbreak
I posted this message on the Hydrangea Forum, but it seems most of the members there are in the U.S. Maybe you can help. I live near the Nation's Capital in Ontario. When we moved to this house 23 years ago, there was a hedge of Hydrangea Annabelle about 12 feet long which provided privacy to our front patio. It was perfect until about five years ago when it contracted what I was told is a "leaf roller". This little vermin takes two facing leaves, glues them together like a little envelope, and proceeds to reproduce therein. Eventually the stem just shrivels up and dies. I was told to treat it with BTK, which I did, but I realize the BTK would have to come into contact with the critter, which it doesn't because it protects itself so well. I have tried taking off the little envelopes but it is time consuming, and you can't get them all. The result of this infestation is that the blooms are smaller, and the bushes don't grow as tall as they used to. This year, I cut them back a little more severely than usual, and now that they're growing out, the infestation seems worse than ever.
I am losing plants every year, and I would hate to have to give up on them, they're a landmark in our neighbourhood. Any help would be greatly appreciated.