15 deg C/59 deg F
This is a genus of about 20 species of tuberous plants from Brazil and Argentina. the most important of which is the well-known gloxinia, and comprising hybrids and cultivars ofspeciosa. These are ideal pot plants with beautiful velvety foliage, extremely neat compact habit, and exceptionally showy trumpet-shaped in glorious colours and colour combinations. An important advance has recently been made with the introduction of I’, hybrid . The plants are vigorous, and quick to flower. From sowings made in January, good can be obtained by early autumn. As this species does not demand maximum light, it is not difficult to grow from seed under window-sill conditions. The simplest and most convenient way. however. is to obtain tubers of the named forms in spring. For example, some good ones are ‘Emperor Frederick’ (bright scarlet with white border, very striking). ‘Duchess of York’ (violet with white border). ‘Princess Elizabeth’ (white with blue border). ‘Red Tiger’ (white, spotted red). ‘Royal Crimson’. ‘Royal Pink’. Mont Blanc’ (pure white). ‘Brilliant Scarlet’. ‘Tiger Ked’ Ired flowers with wavy borders). ‘GregorMendel’ (double-flowered, usually reddish shades sometimes with white picotee edges to petals). Start the tubers into growth by immersing them in a bowl of moist peat in a warm place. Inspect them every
days and as soon as shoots are seen pot up in 12 cm (5 in.), one tuber to each. Set the tubers just level with the surface of the so that they are barely covered. Often it is difficult to decide which is the top of the tuber, but starting them in peat will soon reveal the areas sending out and where the shoots will spring from. All that remains is to keep the pots in a slightly shaded warm place.
Sometimes plants already potted and well under way are sold by garden shops and florists during early summer. If the more advanced stage is wanted, it is best to buy just when the first buds are beginning to open.
After flowering in autumn and when the foliage begins to die down, gradually let the pots become dry. Remove the tubers and store them in clean dry sand in a frost-free place over winter. Old tubers may become corky and they may flower badly. It is then best to make a fresh start. However, tubers can usually be kept for about three years or so..S. regina is a species with boldly veined foliage quite striking for this alone. It is of Brazilian origin and bears beautiful purple rather pendent flowers reminiscent of slreptocarpus. Presumably, the flowers have suggested the common name of Cinderella’s.slippers, although it is difficult to see why. Once known as Gesneria cardinalis but now regarded ascardinalis, Sinningia cardinalis, the cardinal (lower, can also be grown from seed, and there are a number of cultivars. The foliage is oval
in shape and very velvety in texture. The flowers are brilliant scarlet and tubular in shape, borne in an erect cluster from summer to autumn. A species that has recently had some publicity, and also easily raised from seed, is.S. kucotricha, now known askueotricha, and given the strange common names silver song and Brazilian edelweiss. The foliage is delightfully silky and silvery-grey in colour, and the flowers. which are similar to S. cardinalis in shape, are a lovely orange-salmon shade. This species can form quite a large tuber, and it is not generally known that mature tubers can produce and flowers without soil or water, and can be grown as curiosities like sauromalums or col-chicums. As well as from seed, most sinningias can be propagated by up the tubers when shoots are forming, so that each segment has a shoot, and them separately. Some can also be grown from and from cuttings of young shoots..All sinningias like shade and moderate , and should be kept nicely moist during their growing period. When producing leaves they can also be fed. especially if it is intended to save the tubers. Pests and diseases are not often troublesome, but overwatering may cause the tubers to rot. Chills will cause yellowing and sickly or slow growth. and direct sunlight may cause leaf scorch leading to browning and shrivelling.
SMITHIANTHA (.temple hells) 15 deg C/59 deg F This is a genus of only four species and they were once grown under the name ‘gesneria’. These species are not now very often grown, since they have been crossed by plant breeders to produce a range of superb cultivars worth growing for their delightful foliage. This is of a lovely velvety texture and often subtly coloured, with an iridescent sheen or texture. The striking flowers are borne on long spikes above the foliage and often have colours giving unusual contrast to the foliage tints. The form of the flowers and the country of origin of the species has also inspired the common name Mexican foxglove, although this does lead to confusion with the tiny Tclnmeniti mexicana which has the same common name. The plants arefrom rhizomes. best bought from a specialist nursery. started into growth as described for gloxinias ipage 120). However, it is better to start earlier, in February, and in a temperature of 15-18 deg C (59-65 deg F). The rhizomes can be potted singly in 15cm (5 in.) pots or three to a larger pot. but avoid mixing the named cultivars. The treatment from then on is much the same as for gloxinias, but singly-potted plants can have the growing tip removed when about 5cm (2in) of growth has been made. This delays flowering for a ’vv weeks, but results in nicely shaped bushy plants. It is important to water cautiously at first after potting, gradually increasing the amount given until leaf growth is well under way. Water should then be applied freely. Some recommended names are Orange King’ (bright orange/yellow flowers: bronzy-green foliage). ‘Scarlet Emperor’ (scarlet flowers with golden-yellow throat and edged red). ‘Abbey’ (green foliage: peach flowers). ‘CarmelT (red-tinted green foliage: cream flowers spotted red), and ‘Cathedral’ (green leaves: yellow-orange flowers). Flowering usually takes place from late summer to autumn. During growth and flowering a moderately humid atmosphere should be maintained, and wide temperature changes avoided. After flowering gradually reduce as for gloxinias, but store the pots on their sides when dry in a place well free from frost. Next planting time the pots should be very carefully emptied and the rhizomes, which should have multiplied, separated and started as already described. Handle them carefully because they are brittle and easily damaged. The species.S. zerbina is sometimes sold as a houseplant when in flower, or almost so. The foliage is heart-shaped with irregular edges and prettily mottled in chocolate brown against an olive-green velvety background. The flowers are scarlet with yellow throats, and this species crossed with S. fulgida was used by Cornell University in America to produce some of the named forms already recommended. Smithianthas are not particularly prone to pests or diseases, but chills, wide temperature changes, excessive sunlight. and a dry atmosphere, or over-watering. can bring about deterioration or poor growth.