This week, a question of prevention.
Q: I have golden euonymus and crapemyrtles that have had scale problems several years running. Is there anything I can do to prevent this problem next year? I use the drench insecticides each year and they work, but I’d like something less toxic.
A: There is!
This is the season for applying dormant oil to kill scale and the overwintering eggs of many pest insects. Pick a mild one- to two-day window, with temperatures under 70 degrees and above freezing, and spray to completely coat the plants, leaves, stems, and all. Dormant oil is far less toxic than most pesticides, and kills insects by smothering them, rather than poisoning them. The window for dormant oil applications opens now – wind up dormant sprays before temperatures warm up too much. Dormant oil goes a long way per dollar spent treating your plants, so it’s an inexpensive way to greatly reduce your pest problems next year.
Try to get any applications of dormant oil done before new growth begins on your plants. Do not spray when temperatures start to rise over 85 degrees or you can potentially damage plant leaves, particularly those of species with fuzzy or hairy leaves.