There are two types of these small-scale replicas of summer-flowering tuberous begonias: hiemalis, the larger and more lavishly blooming; and cheimantha ("Christmas begonia") with smaller single flowers in white or shades of pink. Both types flower in winter but do not necessarily go completely dormant in summer.
Cheimanthas bloom from November to March in draft-free, humid but fresh air, soil constantly moist but not soggy; plenty of bright light but not much direct sun. When flowering stops, cut plants back severely, continue to keep cool and moist until new shoots appear. When these have two or more nodes, cut them off and root them in a propagating box for the next year's plants. Recommended: 'Carolina', 'Marina', 'Spirit of Norway', 'Gloire de Lorraine', 'Marjorie Gibbs', and 'Lady Mac' which is often listed as "Christmas White" or "Christmas Pink" begonia.
Hiemalis begonias, with showy double flowers or dogwood-like single flowers up to 4 inches across in white and shades of pink, red, salmon, and apricot, are more susceptible to mildew and rot than the cheiman-thas, but the plants can be saved from year to year.
'Apricot Beauty', 'Emily Clibran', 'Baardse's Wonder', 'Fairy', 'Pink Perfection', 'Snowdrop', 'The President'.