If your clematis start off well in the garden but then gradually wilt and fade away it is the problem called clematis wilt, and it differs from almost all other wilt diseases of plants in that there is no obvious fungal or bacterial cause. The symptoms are always the same: the plants grow well for two or three years and then simply fold up, with blackening of the shoot tips and dark scars on leaves and stem.
The cause is not fully understood and treatment is difficult to say, but the following routine may help.
– Because a leaf-infecting fungus may be involved, spray with a systemic fungicide as soon as the wilt appears. – Use the same fungicides to drench the soil around the plants.
– Then cut the plants back hard, either to a live bud (if there is one) or right back to ground level. Often plants affected with wilt will regenerate from the base in the following year.
If the treatment fails and the plants do not recover, dig them up. If you plan to try another in the same spot, dig out a hole -at least a 3ft cube – and replace the soil with a fresh supply from somewhere else in the garden.
Clematis wilt does not affect any other type of plant, so it will be quite safe to use the soil on beds and borders. Unfortunately, no varieties of clematis are known to be genuinely resistant to the disease although, in some gardens, some fare better than others. The moral, therefore, if you have experienced clematis wilt is to try several different varieties and species when you replant.