Clematis are so easy to care for that the question of the details of how to cut them back quite often only comes to mind when “the wild undergrowth on the house wall” clearly needs a pair of scissors … until then, the clematis was just there and doing what Vines just pretend: they grow and climb upwards. Here are the instructions on how and when to use the scissors on different clematis.
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Recommendations for pruning
If you are looking for information on clematis pruning, you will quickly find that clematis pruning is one of the most important issues in clematis care. Not much later, you will find that there are many contradicting pruning recommendations to be found in articles on clematis pruning care. So that you can decide which statement about the clematis cut makes sense and which does not, the following instructions provide justifications.
So much in advance: The pruning plays just as big a role in the cultivation of a clematis as the care – so all in all a very minor role; Clematis are easy to cut and easy to care for . Caring for a clematis can usually be done without instruction if you have already planted and raised any other plant in the garden. Before you cut a clematis, you should be informed that there are three different pruning groups for the clematis, because there are also three different flowering times for the clematis.
But all clematis get their very first cut at the same time, regardless of the time of flowering:
For everyone: construction cut after planting
The newly planted clematis is cut back to about 20-30 cm above the ground towards the end of the planting year (November, December) . Also the spring bloomers among the clematis varieties, although you cut away the flower systems for the next season with those with the plant pruning. This first year’s flowering would be pretty puny anyway, so doing without these few flowers in favor of promoting plant development is no great sacrifice.
Planting is usually done in late summer because this is the best time to plant clematis in terms of soil temperature. Clematis that were planted earlier or later in the season should also have the top cut. The pruning is especially important for clematis that are planted (too) late, so that the clematis can concentrate on taking root quickly “without being bothered by large, hungry masses of plants above the ground”.
When the clematis has grown, the following pruning rules apply:
Cutback group 1
The pruning group 1 includes numerous wild species , the varieties of the subgenus Ahabene (C. alpina and a few other less commonly cultivated species; so-called Atragene group), C. montana and all hybrids bred from these species.
These are species from mountain regions and other altitudes in the northern hemisphere, all of which bloom in early spring, usually April to May. With the main flowering early, they are excellent nutrient plants for bees and bumblebees.
The pruning group 1 is best not pruned at all , its shoots can withstand any winter cold without damage. But it can be cropped, and sometimes it needs to be cropped. A cut is absolutely necessary, for example, if the clematis becomes too dense inside, threatens to grow old / bald or if it goes its own way in another undesirable way (leaving the climbing aid). If pruning is required, these clematis should be done immediately after flowering in late spring.
Because the species of pruning group 1 belong to pruning group 1 because they create the spring buds in the summer and autumn of the previous year (bloom on the old wood, on the previous year’s wood). The bud development begins when the “old” flowers have faded, so with a cut in summer or autumn you cut off the flowers of the following year. Only when pruning directly after flowering does the plant have enough time to plant buds for the next year.
Pruning group 2
Pruning group 2 gathers all clematis that bloom twice a year . Usually large-flowered hybrids, although one or the other natural species may have a second flowering, mostly with flowering dates in May / June plus August / September. Like C. alpina and C. montana , these clematis bloom in spring. But not with the buds created in the previous season, but with short shoots that develop in the current season on the wood of the previous year. Last year’s wood should therefore be available , as well branched as possible, with plenty of space for short shoots with spring blossoms.
Pruning stimulates branching, when these clematis start the season freshly pruned, more short shoots will develop than without pruning. Freshly pruned, these clematis start the season when they are pruned shortly before the onset of dormancy in November / December, but also when pruned in spring shortly before the start of budding.
Therefore, both are recommended for this pruning group, with corresponding disputes among the experts. The representatives of the pruning in late autumn, however, the climate change is playing more and more arguments: year after year the winters are milder, the clematis sprout earlier and earlier – pruning in the time before the start of budding requires careful observation of the weather and plants, and those who do not observe closely enough , cuts away short shoots that have already formed and with it the flowering of the season. When pruning in late autumn, you will not have to deal with such difficulties. Every 4 – 5 years this pruning should be a little stronger to prevent the clematis from balding: Shorten the shoots by half, with older plants to about one meter above the ground.
You can still take action in spring , but in very late spring : when the first flowering is over in spring, the large-flowered hybrids of this pruning group form new long shoots that bloom again from summer to late summer. If you subject the clematis to a light summer pruning in June, during which you remove the fruit clusters and the pair of leaves underneath, the double-flowering clematis will sprout again really happily. You can look forward to a really lush second late summer bloom after about six weeks.
Cut back group 3
Pruning group 3 includes the vigorous hybrids and wild species that only bloom in summer. These are essentially Clematis viticella , all non- climbing perennial clematis (Tubulosa group with C. integrifolia, C. diversifolia and C. heracleifolia Tubulosa group) and summer-flowering hybrids such as the well-known Clematis x Jackmanii. In addition, a few rather rare clematis: yellow and late-blooming representatives of the Tangutica, Orientalis, Vitalba groups (which climb to a height of 10 m, but do not necessarily have to be pruned every winter).
All these species and varieties bloom on the long shoots of the current season, especially towards the end of the shoot the flowers show up in masses and should do so again next year. The shoots from the last season must be shortened beforehand; in principle, pruning in late autumn or spring pruning shortly before the start of sprouting is possible again, about the pruning date there is the same dispute as with pruning group 2.
For the same reasons as there, cutting in November or December is recommended today for pruning group 3 ; but here you can / should go to work quite radically – these vigorous clematis need a strong pruning to a short distance ( 20 – 50 cm) above the ground every year in order not to “get out of hand” completely.
In case of doubt, only your own decision will help
The “three cut groups of clematis” are sometimes described as if they were special rules that only apply to clematis. Established by a historic clematis breeder and handed down since then, a violation of the iron laws almost blasphemy.
It’s not like that, every clematis is simply pruned with regard to its flower development.
“Generally speaking,” you could prune your trees and bushes at some point in the year. Cut at the beginning of the growing season, e.g. B. for branching, when pruning in summer the wound healing works best, pruning in the winter rest period has the advantage of deciduous plants that the structure of the plant can be clearly seen. There are many other reasons to do certain work on a plant at a certain time.
Sometimes the reasons are to be found in the old days, for example the fruit trees, which were not particularly good at closing wounds in winter, were still pruned in winter for a long time because the farmers did not have time to do so in summer. Today there are no more farmers with fruit trees, but there are masses of monocultures in the area, where all sorts of threats multiply excessively – summer pruning of the tree in full force becomes advisable. Sometimes the reasons make sense, such as the recommendation to prune clematis in three pruning groups at different times. These are simply the times when next season’s bloom won’t suffer from the pruning.
The cutting groups are by no means restricted to clematis, for example, forsythias, hydrangeas and rhododendrons also create the spring buds in the summer and autumn of the previous year and “thus belong to cutting group 1”.
A trim at times other than those specified for the trim groups can be useful / necessary for several reasons:
1. Ignorance of the variety
If you are growing a clematis whose botanical name you do not know, you can either scroll through lists of varieties in order to assign the plant precisely; or classify them in a pruning group yourself and after carefully observing the plant. In case of doubt, the latter is certainly better for the clematis …
2. Other needs
The cutting groups only give a rough direction, other needs can lead to different cutting times.
The Texas clematis C. texensis, which migrates in winter, is often assigned to cutting group 3 because it has to be pruned every year and in winter. However, pruning right at the beginning of winter could cost these clematis their lives if bitter frost occurs later in winter – “pulling in” means “freezing away above ground when frost comes, but until then protecting the survival of the roots through the plant matter above the ground sprouts completely new in spring ”.
It is also possible that there was simply not enough time to prune the clematis according to their pruning group. Then the pruning must be made up later, which is possible for all three pruning groups by a pruning shortly before the start of budding (in February / March). Under these circumstances, however, double-flowering hybrids should occasionally return to simple flowering.
Furthermore, there are said to be clematis of cutting group 3 that did not notice that they were expected to grow quickly and vigorously. You can leave such plants alone or just shorten them a little all around as long as they keep their growth at a snail’s pace. But under careful observation, even with plants, there should be late starters.
3. Hybrids that cannot be classified
There are hybrids with clematis from several pruning groups. Which cutting group such clematis should be assigned to is often controversial among experts.
You can start here to deal with the statements of the experts or make a self-determined decision as described under 1..
4. Hardly known exotic species
There are rare scented clematis and representatives of the C. flammula, C. armandii and the Florida group that have not yet been assigned to a cutting group because they are usually only traded among lovers. If you have found such a rarity, only the source of supply or a proven clematis specialist can give you details about the trimming (which does not necessarily have to be done according to the strict scheme of one of the cutting groups).
Conclusion: cutting clematis is quite straightforward; Finding out the best time to cut a clematis, on the other hand, can be quite laborious. Even if you know which cutting group your clematis belongs to, this is only a rough guide that, in case of doubt, will not save you from making your own decisions …