Clematis

Question

When should I prune clematis?

Answer 1

As these articles explain, the best time of year to prune clematis depends on which species you have and which pruning group it falls into:
https://www.gardeningknowhow.com/ornamental/vines/clematis/pruning-clematis-vines.htm
http://web.extension.illinois.edu/cfiv/homeowners/090306.html

If you don't know what type you have, you may be able to figure it out based on the characteristics and timing of the blooms, as explained in these articles:
https://extension.psu.edu/plants/gardening/gardening-questions/spring/when-should-i-prune-my-clematis
http://www.clemson.edu/extension/hgic/plants/landscape/groundcovers/hgic1104.html