Severely diseased variegated English holly. Photo by R. Regan.

Plant Damange:
Foliar leaf spots, shoot blight, and stem cankers.

Single Host:

• Holly (Ilex)

Infected leaves are an important part of the Phytophthora disease cycle on holly. Photo by R. Linderman.

Occurrence
This disease is found in holly orchards and in both field- and container-grown nursery crops. While disease development is favored by cool and misty conditions, it can be found wherever holly is grown in western Oregon.

Infection
Spores infect pruning wounds, spine punctures, and leaf scars. During warm conditions, this disease subsides; after a prolonged hot summer, the pathogen’s survival is greatly reduced.

Survival
This pathogen survives as spores in diseased stems and leaves. Spores become active again as the fall rains begin.