Coleus: Greenhouse Plants
W – warm, minimum of 13°C (55°F)
Old World Tropics
Most of the plants grown are varieties of Coleus blumei from Java. Good strong named varieties are available which must be propagated by. These are best taken in summer and root very quickly. The resulting plants grown on through the winter will make good sized plants the following year. Alternatively, there are some very good seed mixtures available. Having grown these you can select out your favourite colours and propagate them on by cuttings. Whichever method is being used it is important to pinch out the tips constantly, starting with small plants at 8 cm (3 in) high. This will cause branching and maintain a good shape as well as discouraging flower production. Flowers are mostly unattractive and quality of foliage is reduced if they develop. It is possible to train standard or fan Coleus if you have the heat to keep them growing throughout the winter and a good strong variety such as Pineapple Beauty. C. b. verschaffeltii, which has purplish-red leaves can be allowed to produce flowers as they are a good deep blue and contrast well with the foliage. Of the species I would only bother to grow C. thyrsoideus from Central Africa which has quite succulent strong-smelling hairy leaves and large bright blue flowers in winter.