ABSTRACT
Distributed mostly in the warmer temperate areas of the Northern Hemisphere, Cercis are usually seen as small trees or large shrubs. They are characterised by handsome rounded heart-shaped leaves; a number of selections, particularly of C. canadensis, produce spectacular violet/purple or golden leaves. A number of species and selected forms must be vegetatively propagated. Cuttings have proved difficult to root, and grafting is the main method of propagation. Experience has demonstrated mostly reliable compatibility between C. canadensis, C. chinensis and C. racemosa when grafted to C. siliquastrum rootstocks. Only C. occidentalis may demonstrate consistent incompatibility symptoms with C. canadensis or C. siliquastrum rootstocks. It is possible that, if obtainable, C. chingii will provide a universally compatible rootstock or inter-stem. Cercis siliquastrum has been the rootstock of choice, mainly because good quality transplants have been available from European suppliers. Good quality vigorous young rootstocks are an important requirement for successful grafting of Cercis.
