Clematis Wilt

Question 1

Clematis Wilt - general information

Answer 1

Generally caused by fungus but also caused by stem damage and excessive growth and poor root condition.

Wilting in large flowered hybrid is probably caused by Calophoma clematidina
Wilting in resistant cultivars is probably the result of environmental problems.
Clematis prefer deep and fertile soil in moist and shaded site but often get planted in shallow, dry soils in exposed sites resulting in root stress leading to poor growth which is often described as Wilt.

Problem for growers and nurseries and occasionally gardeners.

Question 2

Clematis Wilt - Hosts

Answer 2

Clematis spp. Especially large flowered varieties.

Smaller flowered and well established plants seem to be mire resistant.

Question 3

Clematis Wilt - symptoms

Answer 3

Stems dry and whiten, stems may turn black.
Red coloured lesions may develop along stems.
Spread is very rapid and there is no warning of infection.
Young, vegetative growth is more vulnerable than mature woody growth.

Question 4

Clematis Wilt - symptoms associated with fungal infection.

Answer 4

Clematis Wilt symptoms are similar to problems caused by environmental issues.
Symptoms are associated with fugal infection include:

Infection through leaves causes leaves to wilt and petioles turn black this then causes rapid wilting if stems.
Infection through stems causes freshly affected stem tissue to blacken, noticeable when stem are split open.