Clematis Wilt , Clematis Leaf and Stem Spot
Clematis Wilt is a disease caused by the fungual Calophoma clematidina. It mainly affects species in the Clematis genus, particularly the large-flowering hybrid cultivars. It causes shoot wilting but is generally not that commonly found in gardens. It's more problematic for nurseries and specialist growers, it is not fatal instantly but if left unchecked, this disease can kill entire plants. This fungus can survive on dead plant material, organic matter and in the soil. It is important to maintain good practices such as the removal of infected material and tool cleaning to avoid spreading problems. Fungal infection may be confused with environmental stress as the symptoms are similar. Be sure to check for physical damage and pests such as slugs and snails.
Black leaf and stem spots
Rapid wilting of foliage
Presently there is no chemical control available for this problem.
Clematis plants grow best in a moist, deep, fertile soil and partially shaded conditions, with most flowering better with more sunlight. In gardens they are often grown in exposed locations, in shallow, dry soils, avoid sites like these for the best health of your plant. When plants are grown in sub-optimal conditions, they experience more root stress, which leads to poor growth and wilting. Planting deeply, maintaining watering during dry conditions and mulching can all help alleviate root stress. For infected plants, remove all wilted stems back to healthy growth, identify health growth by the absence of black tissue. Dispose of all infected material promptly to prevent further infection.