Propagating Clematis from Clematis Cuttings, Seeds, Layering
Of all the many and varied gardening tasks, the propagation of plants must rank amongst the most satisfying. But whether you want to produce one plant or hundreds of them, the same principles apply, the first of which is attention to detail.
Timing and Record-Keeping
Even if you do adhere to all the principles, your first few attempts (certainly with cuttings and indeed clematis cuttings) will probably not be a great triumph. However, if you do fail first time round, then this will most likely be due to poor timing.
Plants mature according to the seasons, and clematis seeds and clematis cuttings are greatly influenced by changes in weather conditions. During a dry period, for instance, the seed will ripen very quickly, while a stem that is ideal for cuttings will very quickly harden, greatly reducing the chances of its taking root successfully.
Wet weather presents its own set of problems: the seed may rot on the plant, while cutting material may be so full of water that it rots and dies back.
For this reason it is always a good idea to keep a diary or some form of gardening log. If you note down all your successes and failures, together with the time of the year and the prevailing weather conditions, then a pattern will gradually emerge. The data will be extremely valuable, enabling you to increase the percentage of successes and also to monitor the exact requirements for each individual plant.
Healthy Plant Material
It is equally important that you should only use material from healthy and well-grown plants. Any plant that is suffering from starvation, poor growing conditions, disease or insect attack should simply be rejected. The seed will probably not have matured, and any cutting material will have already been damaged.
For the same reason it’s important to feed and water your potential parent plants even more carefully than the rest. They are, after all, going to provide for the next generation. But when feeding them, you should err on the side of caution as far as nitrogen-based fertilisers are concerned.
Concentrate on well-balanced fertilisers with a higher percentage of potash, and you will produce sturdier, healthier plants. Nitrogen promotes growth, but if used in excess it also tends to make the material very soft and sappy, and therefore liable to disease. Potash, on the other hand, increases the sugars in the sap, and this not only promotes hardiness Cut also aids propagation.
Cleanliness is Vital
Whatever tools you use, you must always clean them thoroughly before carrying out each new task. Cleanliness is the over-riding principle here. All too often, perfectly healthy seeds and good cuttings have gone to waste simply because of inadequate hygiene. Sometimes the compost used has been infected with weeds or diseases, or the cutting tools have become infected from other plants.
It doesn’t take long to wave a knife blade through a gentle flame, or to wash your pots and seed trays in a mild disinfectant. Yet these simple measures alone are enough to produce a dramatic increase in the number of plants that can be successfully propagated.
Always Ask Permission
This is one principle that gardeners feel very strongly about. Never take seeds or cutting material from any plant without the owner’s permission. Other people’s gardens, especially those of the rich and famous, may contain some wonderful plants. But don’t be tempted, as so many people are, to take cuttings from a plant in the hope that no one will mind.
The resulting condition is euphemistically known as finger blight – a well-known disease that affects plants growing in gardens that are open to the public. Remember that the gardener may well choose these plants for the very same purpose, only to discover that some unthinking person has removed all the prime cutting material.
Gardeners, almost without exception, are of a very generous nature, and if you ask them they will probably give you far more material than you ever expected.
Tips for Carrying the Plant Material
There remains the problem of how to get the seed or cutting material back home in good condition. For seed, an envelope or paper bag is ideal – not polythene, as this can create problems of overheating or condensation.
For cutting material, there is a handy transportation method that can be used over long periods without the material coming to any harm. Take a polythene bag, dip it in water, shake off the excess and place the propagation material inside. Then blow air into the bag, seal it and place it in a shady place.
Clematis Seed Propagation
Propagating plants from seed is a cheap if not always reliable means of increasing plants. While plants grown from the seed collected from species will be more or less true to type, the seeds from hybrids will inevitably produce totally new hybrids.
The latter can be a useful way of producing new varieties, especially if you’ve carefully planned the hybridisation and chosen the parents with a view to the final goal. However, it can also lead to disappointments, even among the species. Clematis tangutica, for instance, will show marked differences in flower shape and colour when grown from seed. C. viticella, although very easy to germinate, often produces plants with small, muddy-colouredof little decorative value.
So much for the negative side of growing from seed. In the main, however, it is great fun, and while the results — especially with clematis – may not be what you intend, you will often be surprised. You may even fall on an all-time winner such as a red tangutica or a beautifully scented large-flowered hybrid.
The time taken for clematis seed to ripen depends on the species and on the time of flowering. As the seeds ripen, they each develop a feathery tail that is normally used for wind dispersal. Then is the time to harvest the seed. As soon as you’ve collected enough seed, carefully remove the tassels, place your seed in a polythene bag together with some moist sand, and keep it in the refrigerator at just below 40°F (4.5°C) until the following spring.
Once the weather starts to warm up, remove the seed-and-sand mixture from the ‘ridge and prepare a seed tray or pot with some good-quality seed compost. Gently firm it down, and lightly sprinkle the seed and sand over the surface. Give the tray a good watering, cover it with a sheet of glass or polythene, and place it in a shady place well away from marauding mice (who love clematis seeds).
With some, germination can take 12 months or even longer. Once germination has taken place, give the new seedlings more light before potting them on into small pots. At this point it’s a good idea to start feeding the seedlings. Give each of them a weak liquid feed, and insert a small cane up which the young plant can then start to grow.
Keep your clematis seedlings watered at all times, because they are now at their most vulnerable. As they start to grow – and certainly within a couple of months – they will need transplanting into a slightly larger pot. At this stage it pays to pot them into a fairly rich compost, burying a few buds in the same way as if you were planting them out. This will allow the plants to produce even more roots. Also, provided you pinch out the top growth, they will produce nice bushy plants ready for planting out the following spring.
You’ll have to wait three or four years before your clematis will flower, so it’s not a project for the faint-hearted. But always bear in mind that many of the best modern introductions have come from chance seedlings. You never know -yours might be the next one!
If you need to add several plants your stock, then propagation from cuttings is probably the most reliable method, if not the easiest.
The main advantage of taking clematis cuttings is that all the plants produced will be the same as the original source of the material. They are known as clones, and share all the characteristics of the parent plant. It can be argued that they are in fact the same plant. The millions of plants of the variety ‘Nelly Moser’, for instance, can all be tracked back to one single plant.
There are three important points to follow when growing plants from cuttings:
1. Always choose the healthiest and best-grown plant from which to take your cuttings. You will be wasting your time and effort if you try to use material that is yellow from starvation, or thin and weak from being left in the shade.
2. Use a very sharp blade to work with. One of the many craft knives available is ideal, as are single-sided razor blades. Keep the blade scrupulously clean and sharp, and cut the material as cleanly as you can. A ragged cut when detaching material can allow diseases to enter, which can damage the parent plant.
3. Keep the cutting material firm until it is safely in the propagator. Once the material has been detached from the parent, it will not be able to take up water again until it has formed its own roots.
Once you’ve detached your stem, observing these first three points, the next stage is to trim the stem into individual cuttings. Clematis cuttings are usually rooted using internodal cuttings – i.e. those taken from the sections of stem between the leaves. This is simply so that you can obtain as many cuttings as possible from a given length of stem. Clematis will in fact root just as readily from nodal cuttings – i.e. those from the area immediately around the base of each leaf. The choice is yours.
Take your very sharp blade and simply cut the stem into lengths. Cut between the leaves, and again immediately above them, taking care not to damage the buds in the leaf axil. Given that the cutting must not be allowed to wilt, you can reduce the risk of this by carefully cutting off one of the leaves.
Now insert your cutting into some moist cuttings compost. For small quantities a small pot is the best container to use, with the cuttings spaced evenly around the edge (for some reason they don’t root so well in the centre of the pot). In the case of internodal cuttings, the leaf base should rest at or just below the surface. With nodal cuttings the leaf base should be well below the surface. Continue with this procedure until you’ve inserted all your cuttings. Then water them well and cover with polythene.
Give your cuttings plenty of light – but never direct sunlight – and occasionally spray them over with a light mist of water. If all goes well, they should have rooted within a month or so.
What Clematis Varieties to Use and When
The easiest clematis varieties to root, and the best ones to start off with, are the alpinas, macropetalas and montanas. If you take cuttings from these in the spring, they will develop into sturdy plants before the winter, and can be over-wintered in their pots before being planted out the following spring.
The large-flowered hybrids, and cultivars from other species, are more difficult to manage but still worth trying. These will take longer to root, so great patience is needed. There’s nothing worse for a cutting than being constantly removed from its compost for inspection; then its chances of survival will be virtually nil. If the cuttings have not rooted well by mid-August, then it’s better to leave them in situ until the following spring, when they will have a better chance of becoming established. If you do this, then you should keep a regular check on the pots, clearing thesurface of dead leaves during the autumn months to prevent disease striking.
Propagation : Clematis Layering
The most foolproof method of propagating clematis, and a wide range of climbers besides, is the technique known as.
The basic method is very simple: you select a stem from the parent plant that can easily reach the ground and trail along it; then you place a portion of the stem under the soil and wait for it to root. However, there are a few extra precautions worth considering, as these will raise your chances of success to almost 100%.
The basic principle is fine so long as your garden soil is in perfect condition. If not, then you should fill a medium-sized pot with a good-quality compost – John Innes, for example – and sink this at or near the base of the parent plant. Select your stem, lay it across the top of the pot, and cover one or more of the leaf joints or nodes with a little more of the compost. Secure the buried section of the stem with a piece of bent wire inserted into the compost, and water thoroughly.
Make sure the pot is well watered at all times, and within a few months a new shoot will emerge from the covered buds. Once the new clematis plant is growing strongly, it can be detached from the parent and treated as a separate entity.
If the stem you’ve selected is long enough, you can continue the layering process along the stem, choosing alternate nodes. But as the plants take root, always remember not to detach any of them on the side towards the parent clematis plant until all those on the other side are properly rooted.