A few valuable shrubs will not bear propagation in the ordinary ways. One of these is the Amur Tamarix. The successful practice has been to make the cuttings late in fall, tie in bundles with the bases evened, and set the bundles on a bed of sphagnum moss in the cellar. It is not difficult to keep the moss wet. During the winter the process of callusing and rooting goes on and in early spring they are ready to set in nursery. In a warm and quite moist cellar the writer has prepared cuttings of Delaware grape, Rosa rugosa, and some cherries and plums, for nursery planting in this way. A dirt-covered cave or cellar not heated by a drying heating-plant are needed for this interesting system of propagation.
In propagating by cuttings of growing shoots cut from growing branches of herbaceous plants, or the tip growth of woody plants, we are dealing with live, growing vegetation suddenly deprived of the moisture, circulation, and nutriment of the parent plant. The ripe wood-cutting has its supply of starch and plant-food in its cell-structure to aid in starting root and top. If months are required to furnish the needed conditions for growth its contact with moist earth retains its life. But the cutting made from the young and growing parts of the plant must have warm, moist, and more or less confined air where the rays of the sun and rate of evaporation can be controlled.