Dieffenbachia : Greenhouse Plants
T – tropical, minimum of 18°C (65°F)
The first mention of these plants must be a warning that all parts of the plant are poisonous. If the sap is eaten it will cause inflammation of mouth and throat resulting in difficulty of speech, hence the plant’s common name of Dumb Cane. In practical terms this means keeping plants away from the reach of children and never eating whileor handling the plants. Do not let this put you off growing these beautiful as a group of these in a tropical house are delightful. They will not like lower temperatures and leaves will go limp and yellow if they are subjected to them for any length of time. There are many species and varieties available which all need the same warm humid treatment. My favourite is Dieffenbachia X bausei which has a narrower leaf than D. picta and a lot of spots and blotches of white and dark green on a yellowish-green background. Plants frequently produce strange flowers when they are happy. These have the typical spathe and spadix structure common to all plants in the family.
If a plant is becoming too tall and has shed a few lower leaves new plants can be made by taking stem. The shoot tip or tips can be used as 8-cm (3-in) cuttings in the normal way. The stem can then be cut into sections each containing at least two nodes. These should be laid down into a tray of cutting so that they are half buried beneath the . Keep these moist and at a temperature of 21-24°C (70-75°F) and they will root and send up new shoots when they can be potted. The stump of the old plant cut down to within 5-8 cm (2-3 in) of the soil will produce new shoots if kept warm, light and not too wet. This entire operation is best carried out in late spring unless very good heat and lighting is available. Seed is rarely sown but must be fresh; older than two months will be of little use. Bury seed by 1.2 cm (½ in) at a temperature of 24-26°C (75-80°F). Plants prefer a peat-based compost.