Forsythia Diseases: Gall and Twig Blight Identification and Control

Disease Reference Table

Disease	Symptoms	Pathogen/Cause	Management
Galls	Knobby galls along branches.	Uncertain causes. Crown gall, Phomopsis fungus, and genetic abnormality blamed but none conclusively proven. Possibly all three can cause galls.	Prune infected branches. Disinfest pruning shears thoroughly after use.
Twig Blight	Ends of lower branches (especially near ground) die. Black nodules of fungal tissue inside stems when split. Young nodules in pith white at first.	Sclerotinia	Avoid overhead watering in spring. Prune infected branches. Thin shrub for good air circulation. Apply fungicide to protect plants.

Black Sclerotinia sclerotium (overwintering structure) in pith; Twig blight (Sclerotinia) of branch tips.

Plant Disease: Forsythia Twisted Growth: Herbicide Injury Suspect; Baptisia (False Indigo) Diseases: Identification and Management; Calceolaria Disease Management: Botrytis and Phytophthora Control; Fuchsia Disease Management: Rhizoctonia Root Rot and Rust Control; Gazania Disease Management: Downy Mildew and Pythium Root Rot; Amelanchier (Serviceberry) Disease Management: Fire Blight, Rust, and Witches' Broom; Arborvitae Disease Management: Twig Blights and Tip Blight Control; Cotoneaster Disease Management: Botryosphaeria Canker and Fire Blight Control; Privet Diseases: Gall and Twig Blight; Fescue Lawn Diseases: Identification, Prevention, and Control

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