ABSTRACT
External sources provide scions from publicly or privately owned plant collections, or commercial suppliers. Many grafters have sources of scion wood external to the nursery. These can comprise collections in privately owned gardens, arboreta, larger institutions and botanic gardens. Scion selection follows the basic principles; trueness to name, obvious health and vigour, avoidance of any ‘off’ types due to mutations, pest and disease infestation and physical damage. Acquisition is possible by purchase of scion wood from other nurserymen or specialist suppliers. Many can offer a comprehensive range covering the important commercial species, and some grafters rely on this source rather than their own. For many species, scions gathered from growing plants, immediately or eventually destined for sale, are a convenient and satisfactory method of obtaining propagation material. Yield of scion wood for a given quantity of plants/area is so dependent upon various disparate factors that it is difficult to provide accurate figures for planning purposes.
