Ornamental Plum: Scales
revision date: 2023-04-04 12:00
Various species of scales attack ornamental plum trees. Depending on species, scales may be found on the upper or lower surfaces of leaves, or on twigs and branches. Symptoms of scale infestations may include yellowing and/or wilting of leaves on affected plant parts as well as the presence of honeydew, a sweet, sticky material produced by some species of scales. The honeydew may become covered with a dark growth of sooty mold. Scale insects are typically yellowish to dark brown or gray in color and rounded or oval in shape. They are generally 1/8″ long or less.
Use Integrated Pest Management (IPM) for successful plant problem management.
Select non-chemical management options as your first choice!
- Ladybird beetles and parasitic wasps help control scale populations.
- Minor infestations may be picked off by hand.
- If practical, prune and destroy heavily infested branches.
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- Apply a delayed dormant oil just as buds begin to swell to control scale crawlers.
- Homeowners should not make foliar applications to trees over 10 ft tall.
- Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.
Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.