I apply horticultural oil at 2-3% depending upon time of year. I stopped using the term dormant oil many years ago because it can be used throughout most of the growing season.What is the formula you use for dormant oil?
If you do not use dormant oil what do you use instead?
I used to run an operation that treated thousands of hemlocks for the above mentioned pests I stopped using Merit on hemlocks because there was usually a mite outbreak in a year or so. I also stay away from high N ferts as many insects love the flush of new growth.Depends on the pest and the season. Had some hemlocks that were heavily infested with Wooly Adelgid, mites, and scale. Used a 5% solution spring and fall, plus fertilization and merit. (the trees were in BAD shape) They seem to be recovering nicely. Most of the time I go with a 2 or 3% solution. Other than that, I like M-Pede soap for just about everything.