ABSTRACT
Picea grafts, in common with most others in Pinaceae, require low temperatures. It is generally agreed that all Picea species are compatible and no evidence of incompatibility between any combinations have been recorded. For all spruce species and varieties, Picea abies is the favoured rootstock. Spruce are among the most beautiful and elegant conifers; many are large trees, but others are small- to medium-sized and even from among the largest species, such as P. sitchensis, a number of dwarf forms have been selected. Virtually all accounts of spruce grafting in the USA involve grafting during the January–March period, similarly in Scandinavia. An accelerated plug-grown seedling of suitable girth, clothed almost to ground level with needles and some buds present spaced evenly along the stem, makes an ideal rootstock for grafting. In some cases, grafts are stood on open benches with the union buried in a substrate chosen from peat, peat/bark or peat/perlite mixtures; one grafter used sand.
