Three of us answered your question in the one you posted yesterday. http://www.gardenstew.com/threads/can-you-name-my-clematis-variety.38914/
It will die out during fall-winter...cut back after heavy frost or snow..cut all but maybe 3-4 inches..they will regrow on their own. That's what I do to mine..
Find out first which growing group your Clematis is in. Some bloom on new growth and some only on old growth. Pruning it back at the wrong time for that Species will most likely result in either no blooms the next year of considerably smaller blooms next year. https://www.rhs.org.uk/advice/profile?PID=109
@Llecenter, His clematis seems to have only four petals on all its flowers but Jackmanii has 6....is the poster's just an immature clematis?
Worst-case scenario untrimmed: You decide something needs to be trimmed later. Worst-case scenario trimmed: No flowers. Letting it go unless/until there is cause to trim seems like a prudent plan to me with any Clematis, though all of the literature out there describes the different types of Clematis, and various, persnickety care tactics ...that individual schedules might not accommodate, and nobody ever tells the plants they are not receiving the same fuss as other specimens. No plant is naturally evolved to require trimming, but as a technique, it can produce various, fairly reliable results. Trimming anything without a reason, plan, and goal, is often an unnecessary, regrettable endeavor.
Purple, you are do wise! I have always thought all this rigamarole about 4 types of clems requiring 4 different pruning care was a bit much.
What a nice thing to say, TYVM! IDK if that's true, but I won't argue. :+) Some of the stuff I read as a newbie scared the heck out of me. I didn't buy Clematis' because I didn't think I knew enough and didn't understand the types, and thought I wouldn't do the trimming right. I hope others can thwart this intimidation and "just do it."