What's eating my summer skies delphinium?

Summer Skies delphinium (a tall Elatum Group cultivar) is most at risk from slugs destroying spring shoots and aphids overwhelming the tall flower spikes. Leaf miners and delphinium moth caterpillars also attack. Its impressive height makes it a standout target for slugs. Deer and rabbits typically avoid delphiniums due to their alkaloid content.

Hollow or sever new shoots at ground level in spring; ragged holes in leaves Lay iron phosphate bait from first shoot emergence; use copper collars; hand-pick on warm wet evenings

Dense colonies on tall flower spikes and soft new growth causing curl, honeydew, and sooty mould Knock off with water; apply insecticidal soap or pyrethrin spray; avoid high-nitrogen feeding that promotes lush soft shoots

Caterpillars tunnel into buds and spin leaves together; frass and webbing are the tell-tale signs Hand-remove caterpillars; spray Bacillus thuringiensis (Bt) in the evening while larvae are feeding

Pale, winding tracks through leaf tissue; affected leaves yellow and die prematurely Remove and destroy mined leaves; yellow sticky traps catch adult flies; keep foliage dry by watering at soil level