There are more than 1,500 varieties and species of begonias. Begonias originated in many tropical areas around the world. Many named varieties of begonias are greenhouse hybrids that combine genetic material from plants originating in different places. Begonia flowers can range from complex, ruffly flowers to simple flowers that have a fuzzy look.
Begonias are often described as ideal houseplants because of their preference for lower levels of light. In nature, begonias grow in full shade under taller plants. They can thrive indoors in light that ranges from full shade to bright shade. Indoor begonias will not do well in direct sun. Too much light will scorch the leaves and can cause the plant to deteriorate quickly. Do not try to give your begonias too much light.
Soil and Pot
Keep your begonia in a relatively small pot. Begonias growing in larger pots can have problems and may die. Do not repot your begonia until its roots have completely filled a smaller pot. Grow your begonias in soil-less potting soil blends. Soil-less potting soils are generally made of a mix of peat moss and either perlite or vermiculite.
Watering your indoor begonias is not difficult. Give your begonia enough water so that it runs out the holes in the bottom of your pot. Allow the top of your soil to dry out between waterings. Begonias can also grow well using a wick watering method, such as that used for African violets.
Begonias may not do well in overly wet soil. However, humidity is another issue. Begonias need humidity to thrive. If you live in a very dry area, a humidifier can help the plants if you use central heat or air conditioning. If you do not, mist the plants daily and grow them on a humidity tray, which is a ceramic or plastic tray filled with gravel. Cover the gravel with water. The water will evaporate creating a humid zone around your begonias.
Begonias, especially those growing in soil-less media, need fertilization. There are many begonia fertilizers. If you want to use another type, such as fish emulsion or other gentle organic fertilizer, mix the fertilizer one-quarter strength and fertilize your begonias once a week.
Begonias are only cold hardy down to USDA zone 10. They will not tolerate freezing temperatures. If you want to move your begonias outside, be sure that the temperatures will not drop below freezing. In the summer, you can easily keep your begonias outside. However, use caution in the spring and fall.