The first signs of a scale problem are leaf yellowing, branch die back and general decline of the plant. Although very small, scale insects are usually present in large numbers. They form what looks like a crust on branches, twigs, and leaves. Scale insects extract sap and nutrients from the plant, weakening it and making it more susceptible to winter damage and drought stress. Scale Insect Control Scale control begins with a horticultural oil spray in the fall, winter or spring for protection against over-wintering adults.
Treatment continues with sprays throughout the summer to control the crawler stages of scale.
It may take a minimum of 2 years to establish good control for plants infected by scale insects.