Begonias are distinctive in that they can be grown for their attractive flowers or for their attractive foliage, depending on the species. Most begonias are frost-tender and treated as annuals, but some can be grown as perennials in warm climates.
Tuberous begonias are most commonly grown outdoors and are best known for their showy flowers. Wax begonias are also grown outdoors and are frequently used as bedding plants. They bloom all summer long in sun or partial shade. Rex begonias, on the other hand, are known for their colorful foliage. They are often grown indoors.
All begonias like well-draining soil, but some can tolerate more water than others. Tuberous and wax begonias thrive in rich, continually moist (but not waterlogged), loamy soil. Rex begonias are prone to suffer from root rot, so they prefer extremely well-draining soil. They grow best in a planting medium that has a large amount of peat moss and sand. Rex begonias should not be watered until the top of the soil feels dry to the touch, according to the University of Illinois Extension.
Wax begonias that have green leaves grow in full sun or partial shade, while those with bronze leaves do best in the shade. Tuberous begonias grow best if they are planted in partial shade. Some cultivars are trailing, which makes them excellent for baskets on shaded patios. Rex begonias thrive in bright but indirect sunlight. Direct sunlight will fade the colors on their leaves.