Sinningia is one of the most widely grown and loved genera in the gesneriads. Cultivars range from the hugely flowered hybrids of S. speciosa, to the tiny S. pusilla, several whole plants of which could fit in a single bloom of a speciosa hybrid.
This is a large genus native to the rainforests of South America. It has been in cultivation for close to two centuries, with many hybrids produced over the years. The Florist Gloxinia (hybrids of S. speciosa) bear little resemblance to the original species and should be considered a "created" kind of plant. There are many other species and hybrids, however, which are at least as worthy of cultivation, and eminently deserving of the amateur grower's attentions.
Almost all of the Sinningias grow from tubers, storage organs that allow the plant to survive periods of drought, cold or other conditions inhospitable to growth. Under normal conditions, Sinningias will grow and flower, followed by a gradual decline in the plant culminating in full dormancy. After a period with no above-ground presence, the tuber will send up new growth and the cycle will repeat.
Some cultivars can be induced to remain in almost perpetual growth, with no period of full dormancy. Others may go dormant, and never "break dormancy", or begin new growth. But most plants will produce new and better growth after a period of dormant inactivity.
In general, Sinningias should be grown in a medium that retains moisture but allows good drainage. Perpetually wet soil may result in rotting of the tuber, while dry conditions will usually induce premature dormancy. Evenly moist conditions are desirable for most species and hybrids. Regular light fertilization (e.g. 20-20-20 water soluble fertilizer at the rate of 1/4 tsp. per gallon with every watering) is desirable, although some of the more robust cultivars will respond favorably to a more concentrated solution, and some of the smaller cultivars need very little feeding.
The Florist Gloxinia (hybrids of S. speciosa) requires bright conditions, and can be grown very well under bright fluorescent lights or in a greenhouse. Most of the other cultivars do well under lights, and many tolerate windowsill conditions if humidity can be kept up and bright light provided without too much direct sun. A few cultivars, such as S. 'Apricot Bouquet', tolerate outdoor culture in full sun or partial shade, and make excellent patio plants.
