Scale Insects on Boxwood: Identification and Organic Control

Scale Insects on Boxwood: Identification and Organic Control

Long, brown, raised ridges on boxwood branches that scrape off with a fingernail, accompanied by heavy leaf drop, are classic signs of scale insects. These pests suck plant sap, weakening the shrub and causing premature defoliation.

Treatment Options

• Apply horticultural oil or insecticidal soap during the crawler stage (typically late spring) for best contact control.
• Systemic insecticides like imidacloprid (Bayer Tree & Shrub) applied to the soil provide season-long protection.
• Organic alternatives such as Atomic Grow can improve plant health and deter pests by raising leaf brix levels.

Confirm identification with your local Extension office before treating, as other issues can mimic scale damage.