Everyone knows that cuttings (from the old French cut, sprout, germinate) is a necessity for all budding or experienced gardeners, in order to conserve, rejuvenate or multiply the favorite plants in the garden or at home. Nothing could be simpler and easier to implement, provided you take care of a few details that increase your chances of success. The cuttings allow you to reproduce a plant from a piece of stem, leaf or root. This vegetative multiplication - excluding sexual reproduction - makes it possible to recreate the original plant, by true cloning, and to faithfully preserve its characteristics: size, habit, color of the leaves and flowers.
I meet the favorable conditions for cutting
The main time for cutting is probably the end of summer, from the end of July to the end of September. Spring and fall cuttings also give good results. The traditional practice of the gardener fixed the most favorable period, according to the species. It is preferable to take the cuttings in the morning, which are richer in water, and to transplant them immediately. The success rate is higher if the mother plant is vigorous and disease-free. The tools used, grafting machine or scalpel, must be well sharpened and disinfected. The transplanting substrate should be sterile, light and well draining if possible, like special sowing potting soil, or a mixture of light peat and sand. The use of a hormonal powder is sometimes necessary to stimulate the formation of the root system, particularly in conifers and evergreen shrubs. Finally, good humidity, accompanied by gentle heat, under shelter, accelerates and facilitates the rooting of the cuttings. We speak of stewed cuttings, if it is completely covered (by a plastic bag or mini-greenhouse).
I start cutting
The practice of cuttings applies in many cases, depending on the characteristics of the plants and the period of sampling. The cuttings, generally taken from the stem, can be herbaceous (chrysanthemum for example), semi-augured, that is to say in the process of lignification (rose bush), or entirely augured, that is to say with twigs lignified (gooseberry ...). Herbaceous cuttings (many indoor plants) are the simplest. We take a stem or a piece of stem of the year, which we transplant in a suitable substrate. You can even let the roots develop by immersing the base of the stem. Semi-augured or augured samples are taken from a piece of stem in the middle of a branch of the year. Sometimes the sample is extended by a small piece of adjacent twig or only by a piece of bark from the latter. In these two cases, we speak of heel cuttings. The twig or heel must be cut in a bevel to increase the contact surface with the substrate, before dipping it in the hormone powder. To limit transpiration from the cutting, two-thirds of the leaves must be removed without damaging the buds. Dig a pre-hole in the soil, before inserting the cuttings thus prepared a few centimeters deep, and tamp the soil all around. Water moderately.
Other types of cuttings
Some plants have the particularity of reproducing from one of their leaves. A saintpaulia leaf, the petiole of which is planted in the ground, will give a new seedling a few weeks later. Some begonias multiply by spreading an adult leaf on the substrate (we will have made a few incisions in the ribs of this leaf beforehand). The reduced papyrus leaf that is placed in the water "upside down" is an exception, because in all other cuttings, we respect the natural direction of the rise of the sap from bottom to top. Root cuttings concern plants that have the ability to regenerate from their root system: these are perennial plants such as lupine, poppy ... but also shrubs such as lilac, raspberry. It is enough to lay flat 5 cm sections of roots on the substrate, taking the same precautions as for the other cuttings. Now is the time to wait before observing the first signs of departure from the vegetation, confirming that the cutting is "taken". From the first shoots, do not forget to transplant the new plants in a more nutritious substrate, as for those of a seedling.
Cut a rose, a year later ...