"There is a general impression that the method of producing dwarf trees is a secret the Japanese have never divulged, but the course to be pursued is really simple.  The whole system of culture may be summed up as the reverse of nature's method.  It really consists, not in the survival of the finest, but rather in the survival of the unfittest.  A poor, weak seed is usually chosen and planted.  As soon as it has attained some growth the leading shoot is trimmed off.  The little plant then grows two other shoots, and these are carefully watched.  When one shoot exhibits a strength and vitality greater than its fellow, it is at once cut off, and the weaker shoot is untouched in order to form the future dwarf tree's main stem or trunk.  This system of trimming and cutting is followed punctiliously.  Water is seldom used -- only in very small quantities to keep the little plant actually alive.  The tree is kept in a pot too small for its full development, and the roots are constantly pruned.  The shoots are carefully trained and bent to follow the growth of a large tree.  All this requires great patience, but the Japanese never tire watching the growth of the tree from day to day, week to week, and month to month.  When the tree has been growing for about five years, it can then be practically left to take care of itself.  It has become accustomed to its training, and its surroundings, and, like force of habit, follows the course laid out for it.  In this manner some very magnificent specimens of dwarf trees are produced which in their miniature beauty and majesty compare favorably with their big brothers in the untrained forests." 1

1     The Loveland Reporter (Loveland, Colorado), Number 85, February 16, 1920, pg. 2.  No other citation is given for this info.