Carpinus betulus · Tree
Powdery mildew: Improve air circulation and prune out affected branches in dry weather.
Coral spot (Nectria): Prune out infected wood and disinfect tools to prevent spread.
Honey fungus: Remove infected trees and avoid replanting susceptible species nearby.
Aphids: Spray with water jet or use insecticidal soap if infestations are heavy.
Caterpillars: Encourage natural predators like birds and wasps to control populations.