Sambucus nigra · Shrub
Verticillium wilt: Remove and burn affected wood immediately; avoid replanting elders in the same spot for several years.
Honey fungus: Improve soil drainage and remove infected roots; severe cases may require removing the plant.
Aphids: Squash by hand, spray with water, or use insecticidal soap if infestations are heavy.
Glasshouse red spider mite: Increase humidity by misting leaves and treat with horticultural oil or a miticide if necessary.
Elder leaf blotch: Rake up fallen leaves to reduce spores and ensure good air circulation around the plant.