Tuberous begonias (Begonia × tuberhybrida Voss, also known as the Tuberhybrida Group or the Tuberosa Group) are a group of Begonia cultivars, sometimes regarded as some of the most spectacular of the genus. One of the first hybrids produced was B. x sedenii in 1870, a cross between B. boliviensis, collected by botanist Richard Pearce and a species from the Andes. Another species from Peru, B. davisii (named after Walter Davis), was also used in early breeding.

Nomenclature

The University of Vermont recognises the following 13 groups: Other systems confusingly use binomial nomenclature to refer to flower types, by the terms Begonia grandiflora, Begonia multiflora and Begonia pendula. The last two correspond to groups 13 and 12, respectively. The first type, grandiflora (large flowered), is then subdivided by flower form; e.g. Begonia grandiflora erecta.

Cultivation

Tuberous begonias grow best in partial shade or filtered sunlight. Excessive exposure to sunlight can result in burnt flowers and leaves. However, too much shade will result in compensatory growth of foliage at the expense of flowers. Soil When preparing the soil for Begonia tuberhybrida, good drainage is important. Plant a Begonia in a pot with equal parts perlite and coarse sand. Remember that sand has an excellent soil structure as it consists of tiny spaces where air, water and nutrients can move freely.