What's eating my delphinium 'black knight'?

Delphiniums are targets for slugs and snails in spring — new shoots can be wiped out overnight — and aphids colonise stems heavily as they grow. Delphinium moth caterpillars bore into stems, and in some regions deer relish the tall foliage. Protect emerging crowns from the moment growth appears in early spring.

Emerging shoots holed or destroyed at soil level in spring; slime trails visible nearby. Apply iron phosphate pellets around crowns from late winter; use copper barriers; hand-pick after dark.

Colonies on stems, buds, and undersides of leaves; honeydew, distorted shoot tips, and stunted spikes. Spray with insecticidal soap or neem oil; squash colonies by hand; encourage ladybirds and parasitic wasps.

Caterpillars bore into stems causing wilting lateral shoots or collapsed spikes; frass visible at entry holes. Remove and destroy affected stems promptly; apply Bt (Bacillus thuringiensis) spray if moths are observed laying eggs.

Tall stems browsed off raggedly; particular damage in late spring before flowering. Apply deer-repellent spray; use temporary deer netting over the border in vulnerable periods.