The leaves are often deformed and curled. Infected shoots are unable to climb. Gray or black masses of fungal spores are often present on the underside of infected leaves. Spores are dispersed by wind and rain. Spiked shoots should be removed promptly and buried.
Flowers often become infected when blooming occurs during wet weather.
Young cones that are infected stop growing and turn brown. When older cones are attacked, part or all of the petals turn brown and cones fail to develop properly. This disease is uncommon in the Pacific Northwest. Symptoms include yellow veining of the leaves and wilting of leaves and vines. Early symptoms may include wilting on only one side of a leaf.