To grow lush begonias do not need to be tended carefully, and often can survive in less than ideal conditions. Put them in a bright area of the house, with filtered but abundant light. They need a fresh soil that retains a little moisture. You can typically use universal soil mixed with soil for orchids, consisting of pieces of bark and peat.
Watering should be regular and frequent with small amounts of water, so as to keep the soil moist, but not soaked with water. Avoid wetting the leaves, which may be marked or be attacked by mould and rot. Remember to remove the faded flowers from the flowering varieties, because they are often the vehicle for mould that passes through the flowers to reach the entire plant.