What's eating my coloratus euonymus?

Euonymus fortunei 'Coloratus' is most seriously threatened by euonymus scale, a sap-sucking armored scale that coats stems and causes yellowed, dropping leaves. Deer browse it year-round, especially in winter. Euonymus webworm caterpillars can also defoliate stems under heavy webbing. Horticultural oil applied at crawler stage is the primary control.

White male scales and brown female scales encrust stems and leaf undersides, causing yellow patches on foliage and dieback in heavy infestations. Apply horticultural oil in late spring at crawler emergence; prune out and dispose of heavily infested branches. Repeat in summer for second generation.

Caterpillars feed gregariously under conspicuous silken webbing, rapidly defoliating branches from May through June. Remove and destroy webbing nests by hand when small. Spray with Bt (Bacillus thuringiensis) or a pyrethrin-based insecticide if infestations are large.

Foliage, stems, and berries are browsed, often to ground level in winter when other food is scarce. Use physical deer fencing or apply deer-repellent sprays, reapplying after rain. Plant within a protected enclosure for young plants.