Dieffenbachia hybr. ‘Amoena’: Dumb Cane
Some hundred years ago a new genus was introduced into cultivation which was to play an important role, but not until much later. It was a native of tropical America and so could be used only in a glasshouse; homes at that time were too dark and cold and the plants did not thrive there. Besides, dieffenbachia was also waiting for ‘its time’ to come in fashion. And sure enough, the imposing, large, spotted leaves came into their own much later, to-gether with modern architecture, central heating and interior decoration.
The genus Dieffenbachia includes some 30 species distributed from the Antilles and Mexico to Peru. The two most important in cultivation are Dieffenbachia picta from Brazil and D. seguina from the West Indies. The two are very similar and both exhibit marked variability. They are robust plants with a stout stem; the leaves, 3 to 4 times as long as the stalks, which may be up to 20 cm (8 in) long, are coloured green with numerous white or yellow blotches. A reliable identifying characteristic that makes it possible to distinguish between the two species are the leaf stalks: in D. picta they are grooved, in D. seguina they are flat. Several other species, however, have also been used in, for example D. imperialis from Peru, which has nearly 60-cm-(2-ft)-long stalks and equally long leaves with yellow-green blotches. Another important species used in the first hybridizations was D. weirii from Brazil, which is only about 60 cm (2 ft) high with a quantity of white or yellow blotches on the leaves.
Cultivation is easy and almost always successful in the modern home. The compost should be an acid, peaty one. Feed should be applied frequently but in the case of variegated cultivars nitrogen fertilizers should be limited in order to preserve the pale markings (too much nitrogen causes the leaves to turn green). Propagation is also simple. Cut up the stem into pieces about 10 cm (4 in) long, place them flat on the surface in a peat-sand mixture and press them in lightly. The propagator must be kept warm and permanently moist.