THE NURSERY-LIST 301 



Dicksonia. Cyatheacece. 



Propagated by division mostly, but also by spores. See Ferns, 

 page 312. 



Dictamnus (Dittany, or Fraxinella). Rutaceae. 



Seeds should be sown in fall as soon as ripe and covered an inch 

 or so. Seedlings should bloom in two years. Increased with 

 difficulty by division. 



Dictyosperma. Palmacece. 



Propagation as for areca, which see. 



Didymocarpus. Gesneriaceoe. 



Propagated by seeds, when obtainable. Cuttings of young 

 shoots when growth begins, in sandy soil in heat, usually do well. 

 See Gesneriaceoe, page 318. 



Didymochlaena. Polypodiacece. 



Increased by division. See Ferns, page 312. 



Dieffenbachia. Araceos. 



Propagated by cuttings of the stem, cutting into pieces 2 or 3 

 inches long which are dried for a few days, then put into boxes of 

 sand. These cuttings should be potted as soon as roots have 

 formed. See Araceoe, page 239. 



Diervilla (Weigela). Caprifoliacece. 



Increased by suckers and cuttings made in spring, summer or 

 autumn. Hardened green cuttings, handled under a frame in 

 summer, are extensively used by nurserymen. (See page 110.) 

 They are sometimes grown from cuttings in winter from forced 

 plants. Hardwood cuttings, made in winter and planted in 

 spring, like the grape, succeed well. The American native species 

 may be grown from seeds sown in spring. 



Digitalis (Foxglove). Scrophulariacece. 



Raised from seeds, sown in spring, either indoors or in the open. 

 The common foxglove (D. purpurea) often self-sows ; it is best 

 treated as a biennial ; seeds for next year's bloom may be started 

 in spring, or in late summer and handled in a frame to prolong the 

 season. Digitalis may also be propagated by division of clumps. 



Dill (Anethum graveolens). Umbelliferce. 



Raised from seed sown in spring where the plants are to stand. 



