Begonia flowers are hardy, shade-loving plants. Desired for their easy care and showy appearance, they are usually grown as annuals, as they cannot tolerate freezing temperatures. For this reason, they are often grown in pots by home gardeners and brought inside when cooler weather arrives. The appearance of begonias, which feature over 1,500 species according to Clemson University, can vary widely, but they all have the same basic care requirements.
Begonias will grow well in partial shade, but need some exposure to sunlight in order to bloom. Morning sun with afternoon shade is best, because the hot afternoon rays of the sun can burn the begonia's leaves. Begonias will only bloom year-round in USDA growing zones 10 or warmer, but they will bloom as annuals in all growing zones.
Begonias are grown either for their brightly-colored flowers or their beautiful, variegated foliage, which can range in color from bronze, pink and gray to cream and green. Foliage begonias are often grown in full shade. Begonia flowers are either single or double blooms, with delicate, ruffled or smooth petals. Depending on the variety, begonias can range in size from 8 inches tall to over 2 feet tall.
Begonias are striking in masses. Most varieties will not spread to the point where they will become invasive, but they will spread out a bit to fill in an area in your garden or pot. For this reason, they are often planted as bedding plants. Some varieties will droop down over the edge of a container and work perfectly as hanging plants.
Begonias only need basic culture. Indoor begonias should be kept in temperatures between 66 and 73 degrees Fahrenheit. These flowers like moist soil that is rich in organic materials. Potted begonias should be planted in a high-quality potting soil. Garden begonias should be planted in soil that has been amended with organic material. Water begonias often enough to keep the soil moist, but not saturated.
Mealybugs, spider mites and white flies are all known to occasionally bother indoor and outdoor begonias. Begonias in the garden also suffer from scales, slugs and snails. Fungal diseases can attack begonias especially if they are left in standing water, if they are frequently watered from above, or if they are grown during a wet, warm spring. Common fungal diseases include Botris blight, powdery mildew, leaf and stem rot, and Pythium root rot.