Layering is a natural process of propagating some classes of plants which emit roots at nodes and joints when in contact with moist earth.In the case of Carnations and Pinks we take advantage of this phenomenon by deliberately cutting the stem through a joint.
For the layers to root well, they should not be in a hard, starved condition. Remove all the leaves from the growth except from that portion of the layer which will remain above the soil. At all times it is most essential to have a short
layer to commence with—say, one with six fully-developed pairs of leaves, in the case of most varieties.
The best compost is one-third moss-fibre litter or peat, one-third maiden loam, and one-third sharp, fine sand, but any light, sandy compost will suffice. Loosen the soil round the base of the plant and place the light soil or grit from I to 2 inches thick upon the surface.
Have a sharp knife— one with a good point is best—and commence to cut the tongue two joints below where the leaves were trimmed off, allowing the knife to split the stem for i inch or so, or this can be reversed by thrusting the point of the knife through the layer and cutting downwards to make the tongue and trimming off the cut directly under the joint; then fasten down with an ordinary layering pin, taking care that the tongue is not bruised or broken while pushing it into the grit.
In the event of hot weather, water in every dozen layers or so, to prevent the cut being dried, otherwise the emission of roots will be impeded.A layer takes from a month to six weeks to root. As soon as this function has taken place, it is very beneficial to the layers to sever them from the parent plant three days or so previous to potting them. This operation should not be postponed.
It is far better for the layer, when it has become moderately rooted, to be potted into a 3-inch pot or replanted than for it to be left until it has so large a ball of roots that it has to be put in a 5-inch pot; this would encourage soft, quick growth, which is just what is not wanted.