Clematis

The most devastating disease of Clematis is fungal stem rot and leaf spot commonly known as wilt.  Symptoms include a sudden stem collapse typically as the flower buds are about to open, and within a few days, the stems and leaves turn brown or black.   Only one or perhaps a few stems may be infected by wilt.

The cause of Clematis wilt is unknown but the most common theory is that it is caused by a fungus.  The fungus can attack only one shoot, leaving the rest of the plant healthy, including the root system.

Wilt usually affects large flowering hybrids.   We have noticed that wilt is not so prevalent in the fall blooming type, Clematis paniculata or terniflora.

The usual treatment is to remove the diseased stem(s) below the wilted section, even below the soil line.  Plants will usually recover from buds present on the lower stem.