Fighting pests in a pesticide free Ontario can certainly be a challenge. I have found that one of the key solutions is to know your pest, learn it’s life cyle and investigate which organic solution might work. It certainly does make us have to think before we spray which is a good thing.
My boxwood have suffered the last few years from Boxwood psyllid, tiny sucking insects that cause the tips of the boxwood leaves to deform into cups or tight balls. When the cups are peeled open in May, a tiny, grayish green, immature insect is found inside. Although it has not yet killed my boxwood, it certainly does look unsightly. I have often just pruned out the worst areas. This year however, I noticed some white, waxy threads on one of my boxwoods, another symptom of Boxwood psyllid.
Psyllids can be controlled by spraying with insecticidal soap about now when the buglets first emerge from the eggs. A good homemade recipe is 1 tablespoon dishwashing soap to 1 gallon of water.