Clematis are a beautiful perennial flowering vine which many gardeners treasure for their long bloom times and performance in sunny locations. To get optimal performance from your clematis it is important to prune properly. This guide explains the proper time to and how to prune your clematis.

There are three categories of clematis – group 1, 2 or 3 – which require pruning at different times.  If the label on your clematis doesn’t have class information or you just aren’t sure which class your clematis belongs to it’s easy to determine, just go by bloom times. Clematis that bloom in the spring are generally in Group 1, summer and fall bloomers in Group2 and repeat blooms belong in Group 3.

First Year Clematis

Like many establishing plants, clematis require a little extra care after their first year in your gardens. All clematis, regardless of their class, should be give a hard prune in later winter (February – March)

  • Group 1 – Blooms on Old Wood
  • Group 2 – Blooms on Old & New Wood
  • Group 3 – Blooms on New Wood

Ideally, the first year after planting, all clematis – regardless of type – should be pruned back hard, around February or March, to a set of fat buds, to develop good structure. Ideally, again, you should tie the pruned vines into a fan shape, training the base of the clematis horizontally to encourage an open structure that doesn’t hide the blooms. I have to admit to some a great deal of laziness in the “tying in” department. So, remember, “ideal” is just an ideal.

After that, here’s my trick for remembering when and if to prune clematis (for me, the logic of bloom times trumps the letter system any day).

Ask yourself: when do they flower?

Early spring, which is April/May in our climate
These flower on old wood, which means last year’s growth

  • Pruning is optional, right after flowering, if they get straggly or overgrow their space. Or leave them alone. The alpinamacropetala and montana clematis fall into this category (Group or Type 1 or A).

Spring (May-ish) plus a 2nd flush of bloom (August-September-ish)
These flower on old wood AND also on new wood

  • Prune for shape in the first couple of years, then pruning is optional to cut out weak stems or contain the spread early in the season, or tidy up, just after flowering. Many of the large-flowered varieties (such as‘Nelly Moser’ and ‘Bee’s Jubilee’) and some of the doubles (such as ‘Duchess of Edinburgh’) can be treated this way (Group/Type 2 or B – sometimes called Group B1. Is it any wonder we get confused?).

Clematis grow best when on a trellis or support system

Rather than having a gap between blooming periods, these go on and on, given enough fertility and moisture. This group (also Group/Type 2 or B, but sometimes classified as Group B2) includes ‘The President’‘Henryi’ and newer doubles such as ‘Josephine.’ Again, you would prune as for Group B1, above: an optional light pruning in February/March to shape or cut out weak stems, with a tidying, if necessary, after flowering.

They flower on new wood only, meaning on this year’s new growth

Prune back hard to a couple of sets of fat buds a few feet from the ground in Feb/March to keep the blooms closer to eye level, otherwise they can escape from view. Viticella and tangutica clematis as well as the herbaceous or non-twining clematis can be classed this way (Group/Type 3 or C).

How to Prune Your Clematis

How to prune a clematisOn your clematis you want to find a node (also called a leave axil bud) which is a joint on the stem where buds begin to branch out. You’ll want to make your prune just above the node. Remember you’re not going to permanently harm your clematis by pruning it too hard.