Begonia is a genus of perennial flowering plants in the family Begoniaceae. The genus contains more than 1,800 different plant species. The Begonias are native to moist subtropical and tropical climates. Some species are commonly grown indoors as ornamental houseplants in cooler climates. In cooler climates some species are cultivated outside in summertime for their bright colourful flowers, which have sepals but no petals.
The different groups of begonias have different cultural requirements, but most species come from tropical regions, so they and their hybrids require warm temperatures. Most are forest understory plants and require bright shade; few will tolerate full sun, especially in warmer climates. In general, begonias require a well-drained growing medium that is neither constantly wet nor allowed to dry out completely. Many begonias will grow and flower year-round except for tuberous begonias, which usually have a dormant period. During this dormant period, the tubers can be stored in a cool, dry place. Begonias of the semperflorens group (or wax begonias) are frequently grown as bedding plants outdoors. A recent group of hybrids derived from this group is marketed as “Dragonwing” begonias; they are much larger both in leaf and in flower. Tuberous begonias are frequently used as container plants. Although most Begonia species are tropical or subtropical in origin, the Chinese species B. grandis is hardy to USDA hardiness zone 6 and is commonly known as the “hardy begonia”. Most begonias can be grown outdoors year-round in subtropical or tropical climates, but in temperate climates, begonias are grown outdoors as annuals, or as house or greenhouse plants. Most begonias are easily propagated by division or from stem cuttings. In addition, some can be propagated from leaf cuttings or even sections of leaves, particularly the members of the rhizomatous and rex groups.