A: These white growths are not a fungus, but scale insects; small crawling pests that stay in place, and don’t look much like an insect. The damage these pests do is slow; they suck sap slowly from your plants, drying leaves and making the whole plant look tired.
There’s two good ways to treat these pests. During warmer weather, we use Bonide Systemic Insect Drench around the roots of the shrubs to make the whole plant poisonous to the pests, and during cooler weather, applications of dormant oil will smother the scale. Dormant oil is fine for use in an organic program!
Burton specializes in diagnosing and solving plant problems. If you have a question for Burton, please email him at firstname.lastname@example.org and include photos showing the problem.