Articles

Hydrangea Diseases

Name: Hydrangea Diseases
SKU: ART-3515

Informational table showing disease name, symptoms, pathogen/cause, and management of Hydrangea diseases.

Updated:

November 21, 2023

Disease	Symptoms	Pathogen/Cause	Management
Botrytis Blight	Petals turn brown and fall. Leaf spots form, especially where faded petals have fallen. Flower buds are killed before opening.	Botrytis cinerea	Space plants to ensure good air circulation. Maintain low humidity. Avoid watering late in the day. Remove crop debris. Apply a fungicide to protect plants.
Cercospora Leaf Spot	Tan spots with reddish-brown halos develop on leaves.	Cercospora	Water in a manner that keeps moisture off the leaves. Apply a fungicide to protect plants.
Powdery Mildew	Yellow areas form on leaves. These may become purplish. White, cottony fungal growth forms on the lower surface of the leaf.	Erysiphe polygoni	Apply a fungicide as soon as any mildew is observed.
Virescence	Flowers are green and may be stunted. Leafy shoots grow from the flower parts. Plants decline and die.	Phytoplasma	Discard infected plants. Maintain good insect control.
Viruses	Leaves may be mottled, have yellow spotting, dead flecks, line or ringspot patterns. Plants may be distorted or have flower color breaking (irregular streaks of color), or few flowers.	Hydrangea ringspot, tomato ringspot, impatiens necrotic spot	Plant virus-indexed cuttings. Maintain good insect and mite control. Destroy infected plants.