All the species are readily propagated by means of stratified nuts. Do not allow the nuts to become dry. Artificial cracking should not be done. In stiff soils the seedlings are apt to produce a long tap-root which renders transplanting difficult after the first year or two. The tap-root may be cut by a long knife while the tree is growing, or the young seedling may be transplanted. Particular varieties are perpetuated by grafting or budding with any of the common methods. In the north, they are sometimes worked indoors in pots. Common shield-budding works well, if the sap is flowing freely in the stock. Flute-budding is often employed. The improved native sorts are root-grafted in winter. Old trees can be top-grafted like apple-trees (see p. 90). The "English" walnut (_J. regia_) is mostly grown direct from seed in this country, and the different varieties usually come true. In California, the native walnut (_J. Californica_) is often used as a stock for this species, and flute-budding on branches a half-inch or more in diameter is often practiced. "Twig-budding," or the insertion of a short branchlet or bit of branch which is severed from the parent branch in the same manner as a shield bud, is sometimes employed. =Jujube= (_Zizyphus Jujube_). _Rhamneæ._ Seeds and cuttings. =Juncus= (Rush, Bulrush). _Junceæ._ Seeds. The perennials may be increased by division. =Juneberry= (_Amelanchier Canadensis_, var. _oblongifolia_). _Rosaceæ._ Increased by using the sprouts which form freely about the old plants; also by seeds. =Juniperus= (Juniper, Red Cedar). _Coniferæ._ Increased readily by seeds, which, however, often lie dormant until the second year. They germinate more readily if the pulp is removed by maceration or by soaking with ashes for a few days. Green cuttings, in sand under glass, root easily; or mature cuttings may be taken in fall and placed in a cold-frame, in which they will need little protection during winter. Some varieties require a long time to root. Most of the named varieties may be grafted on imported Irish stocks, which are much used in some parts of the country. They may be veneer-grafted and handled in a cool house. =Jurinea.= _Compositæ._ Increased in spring by seeds or by divisions. =Jussiæa.= _Onagrarieæ._ Seeds and divisions are used for propagating. =Justicia=, including Jacobinia and Sericographis. _Acanthaceæ._ Seeds occasionally. The species strike readily from short green cuttings on a cutting bench or under a frame. =Kadsura=, Sarcocarpon. _Magnoliaceæ._ Seeds. Cuttings, made of nearly ripened shoots, which should be placed in sand under glass. =Kaki.= See Persimmon. =Kalanchoe.= _Crassulaceæ._ Propagated by seeds, but cuttings, when obtainable, are better.