13 deg C/55 deg F

Coleus are remarkable in providing a treasure of exciting and multi-coloured varied leaf shapes very cheaply indeed. Although often named C. blumei, the history of this plant is so long and complicated – and has involved many natural varieties, eultivars and species -that few present-day coleus plants resemble the original. A misnomer about this plant is the description ‘nettle’, as coleus belongs to the labiatae and not to the family of

nettles, which is Urticaceae. Each year, seedsmen introduce new seed strains, and the plants are quite easy to grow from this source, although a greenhouse gives better results than a window-sill. Most of the plants bought are raised from seed, as this is more economical than starting from cuttings. which demand congenial winter warmth. However, if any special type or colour is required, only cuttings can be relied on to give an exact replica. Most houseplant enthusiasts regard coleus as a spring to late-autumn plant. Sub-tropical and tropical species have been involved, and the plants need moderate warmth. Growing plants to form large specimens needs greenhouse conditions. As temporary houseplants. the various forms of coleus are easy to grow and only need to be given a position in good light and to be kept well watered and fed during their growing period. With good treatment, they often last well into winter in warm homes. A final 13cm (5 in.) pot is usually adequate. but for conservatories, where forms such as ‘Red Velvet’ and ‘Rainbow’ reach 1.2m (4ft). larger pots will be necessary.

The colours of coleus are enormously varied and just about every shade imaginable can be seen. Leaf shape is varied and some forms have waved or frilled leaf-edges to enhance their beauty still further – such as the new cultivar ‘Salmon Lace’.

During autumn, coleus form thin spikes of flowers which have no merit and spoil the appearance of the plant. Recently, there has been an attempt to produce eultivars with shorter spikes. In all cases, the spikes are best removed at an early stage.

The new cultivar ‘Sabre’ has an unusually dwarf and compact bushy habit, and the flowers are very much shorter and less freely produced. The leaves are narrow and sabre-like, and there are many lovely colour combinations. Seed of selected strains exhibiting particular colour or leaf shapes can be purchased. Alternatively, colourful mixtures can be bought. When growing coleus from seed on window-sills, remember that the tiny seedlings look uninteresting at that stage and do not have their true colours. These develop later.

Coleus may be attacked by aphids and whitefly. but are not especially subject to pests. Erratic watering may cause the leaves to become limp and brown, or even to fall. Generally, they are easy plants to manage from spring to late autumn, and well worth growing afresh each year from seed.

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