One of the things we have to live within gardening is name changes decided on by the botanists for their own – but not necessarily our – good reasons. Thus what we now have to call smithianthas, may still be more familiar to some gardeners under their old name of gesnerias.
The smithianthas are tender, tuberous-rooted perennials and very attractive plants with their spikes of tubularin red, orange, yellow and apricot shades and handsome foliage. Most of the smithianthas that are available are hybrids. They need a temperature of 16 to 21°C. (60 to 70°F.) from March to August, 16°C. (60° F.) in September and October, and 10 to 13 C. (50 to 55°F.) from November to February. The flowers are borne from July to December.
The Growth Cycle
The tubers should be planted singly in March in 5-in. pots filled with John Innes No. 1 Potting Compost, setting them 1 in. deep in the mixture. Provide moderate amounts of water from the time growth begins and water freely after the shoots have reached a height of 3 to 4 in. With flowering completed, gradually reduce the water supply and keep the plants quite dry until March, when potting for the next season is carried out. When the foliage has died down the pots can be stored on their sides under the staging.
Smithianthas are usually increased by cuttings of young shoots inserted in pots of sandyin spring and for this a temperature of 24°C. (75°F.) is needed. They can also be raised from seed sown in March or April in pots filled with sandy peat. The seeds should be sown on the surface of the compost and germinated at the same temperature recommended for rooting cuttings.