White Powder on Ivy Leaves

Cause

• Ivy is susceptible to the powdery mildew disease caused by a number of different fungi that all produce similar symptoms. Powdery mildew is among the most common and easily recognizable plant disorders that affect nearly all plants, including trees, shrubs and crops. Succulent plant areas are more prone to infection.

Symptoms

• The distinctive symptom of powdery mildew is the appearance of patches of white, talcum powder-like substance on upper foliage areas. This powdery growth is sometimes shaded with gray. There are very tiny, pinhead-sized, fungal spores or fruiting bodies visible within these patches. As disease progresses, the mildew or powdery growth spreads to stems, young buds and foliage undersides as well.

Damage

• The infection causes the foliage to start curling and twisting. This distortion often appears before the powdery patches. Young foliage and shoots are first to get affected. Ivy foliage starts to yellow, dry and brown and new shoots are stunted in growth. Affected plants lose foliage and aesthetic value is significantly reduced. Symptoms are more pronounced during dry, warm weather. Plants that are growing in poorly ventilated areas are more prone to infection.

Control

• Preventative measures include avoiding the use of overhead irrigation, as the prolonged moisture on foliage invites fungal growth. Do not use nitrogen based fertilizers on the plant during late summer. This encourages succulent new growth that is more prone to infection. Remove all infected plant areas and destroy. Do not use infected material in compost. Chemical control options includes the use of sulfur based products, neem oil, triforine or potassium bicarbonate.