This section is from the "American Horticultural Manual Vol1" book, by J. L. Budd. Also available from Amazon American Horticultural Manual, Part One (1902).
The common practice of growing trees and some shrubs and plants from root-cuttings well illustrates some of the varied peculiarities of root-structure. It may be said that all trees and plants which naturally sucker from the surface-roots, or which may be made to sucker by breaking with the plough, or cut with the spade, may be grown from root-cuttings. But this only applies to the surface-roots which are capable of developing adventitious buds naturally or when injured. The deeper water-feeding roots do not develop buds soon enough for use in propagation, but if they come to the air by soil-erosion or in other ways they soon change into surface-roots with an ample supply of starch for the development of buds and even upward growth. It is also easy to graft pieces of the surface-roots successfully, but in no case have we known the pieces of the deep roots to unite with a scion, as they are not well stored with starch.
 
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