In plants in the natural world, the act of reproduction is through the transfer of pollen from the stamens of the male flower to the pistils of the female, either by wind or insects. This results in the fertilization of the female ovaries and eventually the formation of seed. When ripe, the seedpod splits, allowing the seed to disperse, some of which germinates, thus perpetuating the species. In the world of horticulture, the natural process can be controlled by using selected plants to obtain seed, which is known as hybridization. In addition, various methods of taking and rooting vegetative cutting material to increase stock are available.
If the seedlings are to flower in the following summer, the seed must be sown in mid-winter; therefore, it is necessary to have both bottom heat and light. You can, however, raise begonias from seed sown later in the winter or early in the spring, when a warm situation will promote germination just as well. Although there is little chance of seeing flowers that year, the plants will produce tubers by winter, which may be grown the following season. Regardless of timing, the advice is essentially the same.
The following describes vegetative reproduction methods used for tuberous begonias.