Detailed Guide to Hydrangea Pest and Disease Control

Hydrangea Pest and Disease Control Hydrangea green petal disease symptoms: plants are stunted and shrunken; inflorescence color fades, petals usually turn pale yellow-green, flowers are small or absent.

Transmission route: it is caused by infection with mycoplasma-like organisms (abbreviated MLO). MLO mainly survives and overwinters on various perennial plants such as daisy, oxeye daisy, greater plantain, fleabane, corn marigold, and sow thistle, and is mainly transmitted to cause damage through leafhoppers from these plants. In addition, dodder can also transmit the virus.

Control methods

1. Promptly remove and destroy diseased plants to reduce sources of infection. Be careful to clear weeds and other wild hosts around the planting area.

2. Although seeds do not carry pathogens, seeds should also be collected from disease-free healthy plants for propagation; cultivating robust seedlings can improve disease resistance.

3. Use insecticides to control virus-transmitting leafhoppers; promptly clear virus-transmitting dodder to control disease occurrence. Hydrangea damping-off symptoms: near-ground leaves produce water-soaked yellow-brown spots that spread to the stem, causing leaves to dry up and stems to turn black and rot. In moist soil, brown spiderweb-like mold can be seen at the base of diseased plants.

Pathogen: Rhizoctonia solani Kuhn., a fungus of the subdivision Deuteromycotina, order Mycelia Sterilia, genus Rhizoctonia, Rhizoctonia solani. Disease conditions: around 15-18°C, moist soil, and weak new tillers sprouting from plants are susceptible to infection.