What's eating my snowball bush?

Snowball bush (Viburnum opulus 'Roseum') is extremely attractive to snowball aphids, which cause severe spring leaf curl, and to viburnum leaf beetles, which skeletonize foliage in late spring and summer. Its sterile flowerheads do not produce berries so bird damage is not a concern. Prompt spring treatment is critical to protecting the showy flowers.

Colonies of grey-green to bluish-white aphids at shoot tips cause dramatic leaf curling and distortion from the moment buds open in spring. V. opulus 'Roseum' is a primary host and infestations can be severe. Spray with insecticidal soap, neem oil, or pyrethrin early in spring before leaves curl protectively around the colony. Systemic insecticide (acetamiprid) works once leaves have curled. Hand-crush small colonies on sight.

Larvae skeletonize leaves from May onwards; adults continue feeding through summer. This cultivar is a preferred host and can suffer near-complete defoliation, severely impacting the following year's floral display. Remove egg-bearing twig tips (look for rows of tiny pits) between autumn and early spring. Apply horticultural oil before budbreak. Spray young larvae in late April–early May with bifenthrin or cypermethrin before damage escalates.

White nymphal scales on leaf undersides produce honeydew that causes sooty mould on upper leaf surfaces, dulling the ornamental appearance through summer. Spray leaf undersides with insecticidal soap or neem oil in spring and repeat through summer. Yellow sticky traps near plants help monitor adult populations. Multiple applications are typically needed.