If the reasons for multiplying plants are obvious, the choice of the process to be implemented is much less. Let us try to see a little more clearly in the means at our disposal.
The sweetest, but also the most natural method is that of sowing. It is the mode of reproduction par excellence of nature. Easy to master and reproduce, sowing can do just about anything you want in your garden. If the choice of seeds is important in garden centers, it becomes immense as soon as one leaves official distribution channels, for example barter between neighbors-gardeners, but also seed-producing associations. This is the only way to obtain unusual or out-of-trend or even rare species. Nature loves variety, it is the guarantee of a healthy and balanced garden. Its low cost is also an advantage - a few euros per sachet of seeds -, which makes it the most used and preferred method by gardeners. The setting is simple. Outdoors, it is enough to draw a furrow or to dig a simple hole in the ground in which we pour the seeds. If there is a risk of frost, potting is usually done so that the plant grows under cover. Once it has become strong enough to face the outside, it is planted in its final location.
Layering consists of causing a branch from a mother plant to take root, by burying a part underground and letting the end stand out. The buried part will generally produce roots. Then, it will be enough to cut the umbilical link, that is to say the rooted part to give birth to a new autonomous plant. Nature also practices layering. This is how many plants multiply, such as strawberries which give rise to adventitious roots from place to place, which in turn form plants independent of the mother plant. You could say that layering is a gentle and natural method of multiplication resulting from the observation of nature. Layering is mainly used for the rapid and controlled reproduction of species or varieties that would be difficult to obtain by other methods. It should however be known that these "children" exhaust the mother plant and, in the case of fruits or vegetables, harm fruiting and make the whole less resistant to external aggressions.
A little simpler than layering, cuttings are a technique which consists in rooting a portion of a branch by planting it in the ground to obtain an individual identical to the mother plant. Identical, because the cutting is the exact copy (we even speak of a clone) of the plant it reproduces, of which it will retain all the specificities, even the distinctive, even abnormal characters (color, precocity, dwarfism, etc.). This technique works with countless varieties and makes it possible to duplicate shrubs, fruit trees, flowering plants, and more rarely vegetables. The method involves removing (cutting) a twig or stem from the mother plant, and planting it directly in the ground to cause the cutting to take root. The cuttings can be of several types with methods which differ from each other. Thus, a distinction is made between herbaceous, woody, root, leaf, eye, branched cuttings, cuttings which need to be in a bell or not, some requiring heating. Refer to the specific technique for each plant to maximize the chances of success.
Division or splitting
Let's divide to better reign over our garden. It could be a gardener's maxim! What is behind these uninviting terms? In reality, nothing very worrying, it is even the technique that works best when practiced at the right time, the risks of failure being almost zero. Plants, especially perennials, have an annoying tendency to become overweight, to the point of suffocating their neighbors. As they grow, they bloom and lose vitality. It is then time to divide them, to give them a little vigor but also to leave a little room for the girlfriends. Of course, we also use this process if we want to multiply its plants at a lower cost. The technique consists in detaching the rooted stems by cutting the tuft of a plant, to obtain one or more small subjects. You will get as much of it as is reasonably possible to extract from the mother plant.
Grafting is a form of shortcut which intervenes in the multiplication of certain plants. It is not always possible to use other methods. For example, some plants do not or badly cut, this is the case with hardwoods. Seedlings do not necessarily give identical individuals, and layering on a rigid subject can be very complicated!
Grafting allows interesting characters - such as acclimatization to one type of soil or resistance to disease - to be transmitted from one individual to another. There are many other reasons we could cite, but these are the main ones. Grafting consists of welding one part of a plant to another, so that they form one and develop by mixing their characteristics. One of the parts, that which has roots, is called support, "rootstock" or "subject". The other, the piece to be welded, is called "graft". This method is often subject to rejection if the individuals are not from the same family, and they must also have a certain affinity between them. If you try to graft an apple tree on a pear tree, there is a good chance that the transplant will fail. Generally, the graft must have at least one eye (bud) because it is he who will replace the subject (rootstock) to form the new framework of the plant. There are several variants for grafting two individuals, such as crown, double slit, escutcheon, inlay grafting, and others more complex like English grafting, on horseback, using a flying buttress approach. This is for This is the reason that grafting is said to be a matter for specialists, but why not take a chance?