What's eating my flowering cherry 'kanzan'?

Kanzan is a flowering ornamental cherry grown for spring blossom, not fruit, but it shares Prunus pest risks. Cherry blackfly colonises shoot tips, caterpillars (winter moth) eat emerging buds and leaves, and cherry slug sawfly disfigures foliage. Bacterial canker (Pseudomonas) is often triggered by physical damage from pests.

Tightly curled shoot tips densely packed with black aphids from April–May; stunted new growth; honeydew and sooty mould foul the foliage Spray insecticidal soap or neem oil when colonies first appear; plant-oil winter wash; natural enemies (ladybirds, parasitic wasps) often arrive by June

Small green loopers spin silken threads and eat flower buds and young leaves in March–April, reducing spring blossom display Apply grease bands to the trunk and stakes in October to trap wingless female moths; pyrethrin at bud-burst if damage is heavy

Slimy, slug-like larvae on the upper surface of leaves from midsummer, leaving skeletonised brown patches; disfigures the ornamental foliage Dust with diatomaceous earth or wood ash; spray pyrethrin in the evening; pick off larvae by hand on smaller trees

Bark rubbed off by antler fraying in autumn; young Kanzan stems browsed and bark stripped, introducing bacterial canker entry points Fit spiral tree guards or wire mesh around the trunk; deer repellent spray on low branches from August; fencing the tree for the first 3–5 years