- Clematis, especially varieties and cultivars that produce large blooms.
- Clematis wilt is a very common although little understood problem.
- The disease is caused by a fungus known as Phoma clematidina.
- The fungus causes lesions on the plant’s stems which in contact with water, release their spores that spread the infection.
- The disease is thought to also be affected by water-logging, wind and failed grafts.
- Sometimes clematis wilt is caused or aggravated by root damage and damage caused by slugs and insects, possibly transporting the spores.
- The disease is rarely fatal to the plant and new shoots normally reappear in the next season.
- Clematis wilt is often misdiagnosed because damage to the stems and lack of moisture at the roots causes wilting anyway.
- Critical points that define Clematis Wilt are: Leaves going black not brown;
blackening from the top down; rapid onset.
Products containing the following chemical ingredients are all effective on Clematis wilt
Note: It is important to read manufacturer's instructions for use and the associated safety data information before applying chemical treatments.
- Cut back affected stems to ground level
- Avoid plant stress by keeping the soil well fed and mulched.
- Plant more resistant varieties of clematis such as c. montana, C. viticella or C. tangutica.
- Plant Clematis deeply, around 6 inches lower than other plants. This encourages more bud development, so the plant can recover more easily if all the stems above ground need to be cut back.
- Put a shield around the base of the plants to stop infected water splashing up onto the base of the stems. The top of a fizzy drinks bottle is good for this.