I have an Autumn Clematis that grows on an arbor. It blooms beautifully in late summer. Do I cut it back after blooming this Fall? Will cutting it back impact on the fullness for next year? How far back should I prune? Thank you.
You should remove dead blossoms as they lose their appearance. It is up to you whether you cut them back or not. If you decide to do so, you should leave a few feet of vine, so that it will remain well established. Here is an article that will help: https://www.gardeningknowhow.com/ornamental/vines/clematis/growing-clematis.htm