(
Begonia aconitifolia ×
B. coccinea) The different groups of begonias have different care 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. Wax begonias are very attractive, they adapt well when brought inside the house for overwintering and can live up to 4–5 years. 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.
Horticultural nomenclature To describe the flower-shape of a begonia, the following abbreviations are sometimes used: • (S) Single – large single flowers, four usually flat tepals (flower part undistinguishable as sepal or petal) • (Fr) Frilled, Crispa – large single flowers, tepal margins frilled or ruffled • (Cr) Cristata, Crested – large single flowers, frilled or tufted center of tepals • (N) Narcissiflora, Daffodil-flowered – large more or less double flowers, central tepals form "trumpet" • (C) Camellia, Camelliflora – large double flowers resembling camellias, unruffled, solid colors • (RC) Ruffled Camellia – camellia flowers ruffled on edges • (R) Rosebud, Rosiflora – large double flowers with rose bud-like center • (Car) Carnation, Fimbriata Plena – large double carnation-like flowers, tepals fringed on margins • (P) Picotee – large usually double flowers like camellias, tepals with different color on margin blending with other color • (M) Marginata – like Picotee only distinct non-blending line of color on margins • (Mar) Marmorata, Marbled – like Camellia but rose-colored, blotched or spotted with white • (HB) Hanging Basket, Pendula – stems trailing or pendant, large to small flowers single or double • (Mul) Multiflora – low, bushy, compact plants with many small single or double flowers 'Non-Stop' refers to a camellia tuberous hybrid that under certain conditions will bloom 'non-stop' all year round.
Cultivar groups Because of their sometimes showy flowers of white, pink, scarlet, or yellow color and often attractively marked leaves, many species and innumerable
hybrids and
cultivars are cultivated. The genus is unusual in that species throughout the genus, even those coming from different continents, can frequently be hybridized with each other, and this has led to an enormous number of cultivars. The
American Begonia Society is the
International Cultivar Registration Authority for
Begonia, and classifies them into several major groups: •
Cane-like •
Shrub-like • Semperflorens •
Rhizomatous •
Rex •
Tuberous and Semi-Tuberous • × Hiemalis/ Reiger/ Elatior Cheimantha • Thick-stemmed • Trailing/Scandent For the most part, these groups do not correspond to any formal taxonomic groupings or phylogeny, and many species and hybrids have characteristics of more than one group or do not fit well in any of them.
AGM plants The following is a selection from about 70 species, varieties and cultivars which currently hold the
Royal Horticultural Society's
Award of Garden Merit: •
Begonia 'Benitochiba' •
Begonia dregei •
Begonia foliosa var.
miniata •
Begonia 'Glowing Embers' •
Begonia grandis subsp.
evansiana •
Begonia grandis subsp.
evansiana var.
alba •
Begonia 'Green Gold' •
Begonia listada •
Begonia luxurians •
Begonia masoniana •
Begonia metallica •
Begonia solananthera •
Begonia soli-mutata •
Begonia sutherlandii ==Culture==