DELPHINIUM DEWBERRY. 225 



Delphinium (Larkspur). Ranunculacecs . 



Seeds may be sown outdoors in a warm border in 

 spring, or in pans, to be placed either in frames or outside. 

 The old plants of perennial sorts may be cut down after 

 flowering, when young growths will spring from the 

 base, and the whole may be lifted and carefully divided. 

 Cuttings of the young shoots, taken in autumn or spring, 

 will root freely if potted singly and placed in a coldframe. 

 They will flower the following season at the same time 

 as the divisions. 



Dendrobium. Orchidacecs. 



Where a rapid increase of a new or special variety is 

 required, the pseudo-bulbs that are more than one year 

 old should be cut into lengths, and fastened on orchid 

 rafts, with a layer of sphagnum beneath them. Suspend 

 them in a hot, moist house, if possible, over a water- 

 tank. The advantage of this method is that the young 

 plants do not need shifting after they commence rooting 

 on their own account. The section to which D. aggre- 

 gatum y D. Jenkinsii, D. densiflorum and D. thrysiflorum 

 belong are best propagated by division. (See under 

 Orchids. ) 



Dentaria (Tooth wort). Crucifer<z. 

 Propagated by seeds or divisions. 



Deodar. See Cedrus. 



Deutzia. Saxifragacece. 



Commercially, the species are mostly propagated by 

 green hardened cuttings in summer, under a frame. 

 Hard-wooded cuttings may be taken in autumn, and be 

 treated in about the same manner as currant cuttings (see 

 pages 67, 68). The deutzias are also propagated by divi- 

 sions and layers. Some of the dwarf sorts are sometimes 

 forced, to make cuttings for winter use. 



Dewberry (Rubus Canadensis and vars., Rubus vitifolius 



and Rubus trivialis}. Rosacetz. 



Seeds are handled in the same manner as blackberry 

 seeds. Increased by layers and, like the blackberry, by 

 root cuttings. Layers are made by simply covering the 

 decumbent canes at the joints. This is the usual method 

 of multiplication. The tips, too, root freely, as in the black- 

 cap raspberries, and it is from these that the commer- 

 cial dewberry plants are mostly grown. See Blackberry. 



