Clematis vines often suffer from a serious fungal infection that causes the stems and leaves to wilt and die back to the ground. There are no approved chemical controls for the treatment of clematis wilt, but several gardening practices help control the symptoms.
For clematis gardens in which wilt has been a problem, applying sulfur-based fungicides helps prevent wilt symptoms. Apply the sulfur in the spring, when new shoots begin to sprout.
Cut off infected plant materials. Clematis wilt does not infect the roots, so plants generally will survive a wilt infection. Cut stems as close to soil level as possible. Cutting away infected plant material helps prevent wilt in new growth.
Plant clematis vines in full sun to partial shade, spacing them far enough apart to allow for good air circulation. Proper air circulation and well-drained soil helps prevent the development of clematis wilt fungi.