Light: Begonias like a lot of light so place them on windowsills that face east or west so that your plants get no direct sunlight but as much light as possible. The early morning sun until 9 am is fine and they enjoy several hours of bright light each day. Avoid southern windows from February through September, as they let in too much light, unless you hang thin curtains that filter the light. Be sure to filter the light coming from western windows.
If you choose to use fluorescent lights, you should place it 6 to 12 inches above your plant. You should keep the light on for roughly 12 hours a day, though some begonia growers leave their lights on for 14 hours.
Temperature: You will want to make sure that the minimum night temperature is 55ºF (13ºC). Begonias do not handle cold well and will suffer from lower temperatures. You can place them outside in a shaded porch area when temperatures are warm enough.
Water: Water your plants when the surface of the potting soil feels dry to the touch. Water your plant until water runs out of the drainage holes. Promptly empty drained water from trays and saucers.
Fertilizer: Optimara 14-12-14 fertilizer every other week.