What's eating my wisteria sinensis 'alba'?

White Chinese wisteria 'Alba' is susceptible to the same pest pressures as the species: scale insects on older stems, aphids on new spring growth, and vine weevil in the root zone. Scale is the most serious long-term concern as it builds up on the extensive framework of stems and reduces flowering. Annual winter inspection and horticultural oil prevent colonies establishing.

Waxy brown scales colonise bark, excreting honeydew that promotes sooty mould; weakened wood produces fewer flower buds. Scrub off with a stiff brush during winter pruning; apply horticultural oil spray on dormant stems; use systemic insecticide in spring for heavy infestations.

Soft colonies on tender spring shoots and flower buds; distorted growth and sticky honeydew may reduce bloom set. Hose off with strong water spray; apply insecticidal soap or neem oil early in the season; encourage ladybirds and hoverflies with companion planting.

Adults create U-shaped notches in leaf margins; larvae feed on roots — a serious risk for plants in containers or recently transplanted. Treat soil with Steinernema kraussei nematodes in late summer/early autumn; use vine weevil drench for pots; improve drainage to reduce egg-laying sites.