|Leaf spot||Large spots form on the leaves, become tan or black in color and may have a zonate pattern within them.||Phoma (formerly, Ascochyta), Botrytis, Cercospora, Cylindrosporium, Phyllosticta, and Septoria||Ensure good air circulation around clematis stems. Remove infected leaves as they are detected. Irrigate plants in a manner that keeps water off the foliage. Apply a fungicide to protect plants.|
|Clematis wilt||Plants with dark brown to black Ascochyta leaf spots develop a stem canker that leads to plant wilting and dieback.||Phoma (formerly, Ascochyta) clematidina||See leaf spot management above. Prune infected stems.|
|Powdery mildew||White fungal growth develops on the leaves. Leaves wither and die.||Erysiphe||Apply copper sulfate, potassium bicarbonate or sulfur as soon as mildew is observed.|
|Rusts||Slightly swollen areas on the vine have eruptions of yellowish spores.||Aecidium and Puccinia spp.||Ensure good air circulation around clematis stems. Remove infected leaves as they are detected. Irrigate plants in a manner that keeps water off the foliage.|
|Phymatotrichopsis and Phytophthora root rots||Wilting and dying plants have a rot at or slightly below the soil line||Phymatotrichopsis or Phytophthora||Ensure good air circulation around clematis stems. Remove infected leaves as they are detected. Irrigate plants in a manner that keeps water off the foliage.|
|Tomato ringspot virus (ToRSV)||Yellow mottling and spotting occurs on leaves.||Tomato ringspot virus (ToRSV)||This virus is moved from infected clematis and some weeds by nematodes. If plants are vegetatively propagated from infected stock plants, new plants will have the virus. Remove infected plants|
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