Plums are extensively grown from suckers, which spring in great numbers from the roots of many species. In France this method of propagation is largely used. So long as graftage does not intervene, the sprouts will reproduce the variety; and even in grafted or budded trees this sometimes occurs, but it is probably because the tree has become own-rooted from the rooting of the cion. It is a common notion that trees grown from suckers sprout or sucker worse than those grown from seeds. Layers are also extensively employed for the propagation of the plum. Strong stools (page 35) are grown, and the long and strong shoots are covered in spring throughout their length--the tips only being exposed--and every bud will produce a plant. Strong shoots of vigorous sorts will give plants strong enough the first fall to be removed into nursery rows. Mound-layering is also employed with good results. Root-cuttings, handled like those of blackberry, grow readily, but some growers suppose that they produce trees which sucker badly. Many plums grow readily from cuttings of the mature recent wood, treated the same as long grape cuttings. This is especially true of the Marianna and its kin (_P. umbellata_), which are grown almost entirely from cuttings. Some sorts of the common garden plum (_P. domestica_) also grow from cuttings. Plums are worked in various ways, but ordinary shield-budding is usually employed in late summer or early fall, as for peaches and cherries. Root-grafting by the common whip method is sometimes employed, especially when own-rooted trees are desired (page 78). In the north and east, the common plum (_P. domestica_) is commonly worked upon stocks of the same species. These stocks, if seedlings, are apt to be very variable in size and habit, and sometimes half or more of any batch, even from selected seeds, are practically worthless. Stocks from inferior or constant varieties are therefore essential. Such stocks are largely imported; but there are some varieties which can be relied upon in this country. One of the best of these domestic stocks is the Horse plum, a small and purple-fruited variety of _Prunus domestica_, which gives very uniform seedlings. This is largely used in New York. The French stocks which are in most common use are St. Julien and Black Damas. The Myrobolan (_P. cerasifera_) is much used in California for standards, but in the east it makes dwarf trees. The peach is often used as a plum stock, and it is valuable in the south, especially for light soils. In the north plum stocks are better. Almond stocks, especially for the French prune and for light soils, are considerably used in California. The apricot is sometimes employed, but results appear to be poor or indifferent, on the whole. Prunes thrive upon the above stocks