Boxwood Mite

Boxwood mites cause a stippled, bronzed appearance on boxwood foliage, particularly on lower and interior leaves where humidity is high and air circulation is poor. You will see fine speckling on upper leaf surfaces and tiny mites on the undersides when examined with a hand lens. Damage accumulates through the growing season and becomes most visible by late summer in Western Washington landscapes.

Improve air circulation by thinning dense boxwood growth during dormant-season pruning. Strong water sprays directed at leaf undersides dislodge mites. Predatory mites provide effective biological control when conserved. Horticultural oil in late winter targets overwintering eggs. Avoid shearing boxwood into dense shapes that create the humid conditions mites prefer.