Clematis (Clematis spp.) are flowering vines that bloom in a variety of colors. The evergreen or deciduous plants come in a range of mature forms and are adapted to growing in all areas. Clematis is susceptible to rot disease that causes foliage to brown.
Root rot is a fungal disease caused by the phytophthora fungi. The fungi also cause crown and collar rots in many plants including clematis.
When the fungus infects the roots, it disrupts the distribution of water and nutrients in the plant, causing foliage to brown and discolor. These symptoms are often accompanied by premature leaf drop. As disease progresses, plant growth is stunted and there are stains and cankers on the trunk. Often there is a reddish or black secretion of sap from infected bark.
Avoid planting in poorly drained sites and wet ground. Use resistant species in areas with known cases of phytophthora. Chemical control options include the use of fosetyl-al foliage spray. The fungicide is effective only when accompanied by adequate cultural management.