Get Planting .... glorious gloxinias
Gloxinia, or sinningia, are the regal beauties of the houseplant world and not difficult to grow, particularly if you already grow African violets (to which they’re related) or tuberous begonias. The large, velvety leaves are a great foil for the sumptuous tubular flowers that come in a range of vivid colours from early summer if planted in the next few weeks.
If you fancy something different, try the multi-tubered species Sinningia tubiflora, which produces narrow, tubular, lemon-scented flowers on long stems in midsummer. Grow gloxinia as you would a begonia or cyclamen tuber, with the rounded end covered sat in compost, leaving the indented growing point level or just proud of the surface to help prevent rotting. Use a shallow pot no more than 13cm (5in) in diameter filled with a peat-free, multi-purpose compost with added shredded bark or Perlite for drainage. Keep compost just moist, but not constantly wet, particularly when the tuber is just starting into growth, and maintain a temperature of 18-30C
(65-86F).
Gloxinias prefer semi-shade so are ideal for an east, shaded west, or north-facing position or keep shaded in a greenhouse. Water carefully if watering from above or dampen compost by soaking from below. Raise humidity by sitting the pot on a saucer filled with moist pebbles. Feed with a liquid houseplant fertiliser once in active growth.
To keep a gloxinia for the following year, start reducing water in autumn, allowing the foliage to die away. Keep tubers just moist in a frost-free conservatory or greenhouse, then repot with fresh compost in spring and start the cycle again. Conversely, keep tubers of S. tubiflora cold and dry, but not frosted, over winter. Grow them hard by positioning in full sun, don’t over feed and keep potbound for best flowering results.