Some of the shoots on my clematis are wilting at the tips, shrivelling and dying back. What has caused this?
There are a number of possibilities for this type of symptom, and a bit of detective work may be necessary to establish the cause.
Slugs and snails enjoy feeding on clematis and may graze away the surface of the stems, giving them a pale or silvery appearance. Young shoots are particularly susceptible.
The plant can suffer from root diseases such as honey fungus and Phytophthora root rot. Waterlogging can also cause root decay, in both soil- and container-grown plants. Plants that have been overpotted (i.e. potted into too large a container) are most at risk of wet, rotten roots. Roots of container plants are also vulnerable to damage from vine weevil grubs. All of these problems prevent adequate water uptake through the roots, leading to wilting.
Unsuitable growing conditions, particularly hot, dry soil, will often result in a weak, unhappy plant that wilts and dies back. Physical damage to the stems (e.g. from strong winds or rough handling during tying in of shoots) is also sometimes involved.
If your plant is a large-flowered hybrid, then the fungal disease clematis wilt could be involved. This disease is often first to be blamed, but it can be seen from the above that many cases of wilting clematis are not caused by clematis wilt! Many of the species clematis are resistant to this disease.
One of the stems of my plant has died and is producing a white, foul-smelling ooze. What is this?
Your plant is affected by a problem known as clematis slime flux, caused when bacteria enter the stem via damage.