|There are 3 categories of clematis for pruning purposes: Spring Bloomers, Summer or Fall Bloomers, and Repeat Bloomers. If you don?t know which pruning category your clematis falls into or maybe even what type of clematis it is, watch the plant for a season and check when and how often it blooms. Spring Bloomers flower on last year?s growth. Prune them back as soon as they finish blooming in the spring and they will have the whole season to put on new growth and set buds for next year. You can prune vigorous growers almost back to the ground if that suits your purpose, but it?s not necessary. If there is very old wood on the plant, avoid cutting into it, since it is less likely to resprout. That?s another good reason to prune your vines regularly. Summer and fall bloomers flower on the current seasons growth. You don?t have to prune summer and fall bloomers at all, but they will continue to grow, probably becoming tangled into a mess, and flowering will eventually diminish some. Pruning seems beneficial and should be done either while dormant or when just waking out of dormancy. You could hack clematis in this category back to about 12 inches, if necessary. Something like Sweet Autumn clematis (C. terniflora), that will reach out and swallow the rest of your garden, will benefit from this drastic pruning. However, if you have a summer or fall bloomer that you would like to remain long, perhaps to cover an arbor or grow through a tree, prune just to a healthy leaf bud. If you?ve been a bit negligent about pruning a summer or fall bloomer and would like to do some remedial pruning, you ay sacrifice some of this year?s blooms, but it should be worth it in the long run. Repeat Bloomers. This group is a little tricky. Some clematis bloom profusely in spring and again sporadically later in the season. Others will offer a few blossoms in spring and a better show on newer growth, later in the season. Either way, pruning in whichever season is going to cost a few blooms. The easiest approach is to watch the plant and determine which season offers the best display and then do your pruning accordingly. If spring is the big show, prune after the spring flowers have faded. You will lose some late season bloom, but gain next spring. Conversely, if late season is the show stopper, do you pruning in while dormant or in early spring. Whichever approach you choose, don?t prune these clematis as severely as categories 1 & 2. Treat this pruning more like deadheading or a means to thin out the plant. Basically it comes down to whether the plants bloom on new or old wood and then how large a plant you want your clematis to be.