Clematis are one of the most popular groups of garden perennials. These flowering vines can be worked over an arbor, threaded through other perennials or secured up a tree. Growing them is fairly easy. But pruning clematis tends to instill fear in the stoutest of gardeners. This fear is unwarranted since pruning clematis simply breaks down to a question of when your clematis blooms.
We prune clematis vines to encourage new growth, which results in more flowers.
No matter which pruning category your clematis plants fall into, flowering will diminish on all clematis vines without pruning. Left unpruned the new growth is confined to the tops or ends of the vines and that is where your flowers will be.
There are 3 categories of clematis for pruning purposes:
- Spring Bloomers
- Summer or Fall Bloomers
- 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 blooming clematis 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.
- Slower growers should be treated more cautiously, pruning just enough to shape the plant or to keep it in bounds.
- 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
- Summer and fall bloomers flower on the current season's 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.
- This group is a little tricky. Some clematis blooms 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 the late season is the show stopper, do you pruning in while dormant or in early spring.
- Whichever approach you choose, don’t prune this 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. Here's a quick list of when clematis varieties bloom and what pruning category to put them.
Here's a listing of Clematis species by bloom period. Refer to the breakdown on pruning clematis to see when the best time is to prune spring, summer/fall or repeat blooming clematis vines.
Clematis Pruning/Blooming Categories
|C. alpina||C. crispa||C. florida|
|C. armandii||C. x durandii|
|C. cirrhosa||C. heracleifolia|
|C. macropetala||C. integrifolia|
|C. montana||C. orientalis|