For beautiful foliage and a constant display of color throughout the season, grow begonias.
While most begonias will be between 8 inches and 2 feet tall, growth habits will vary widely with different species and cultivars.
Begonias are grown for their foliage and or attractive flowers. Some begonias, such as wax begonias and newer hybrid begonias, will continually flower throughout the summer. They can be used as bedding plants and in window boxes, hanging baskets, and other containers. Another benefit of planting begonias is that they are deer and rabbit resistant.
Disease problems associated with begonias include Botrytis blight and stem rot, powdery mildew, and Pythium root and stem rot. The major pests of begonias are mealy bugs, spider mites, thrips, scales, snails, and slugs. Begonias may be sensitive to insecticidal soaps. For more information on how to test a small application area for sensitivity, see HGIC 2771, Insecticidal Soaps for Garden Pest Control. Begonias are also vulnerable to viruses transmitted by thrips like Impatiens Necrotic Spot Virus (INSV) and Tomato Spotted Wilt Virus (TSWV). Viral infection can cause distorted leaves, black patches on the leaves, or light-colored rings or wavy lines to form on the leaves or blooms. Remove infected plants to mitigate the spread of viruses. For more information on insect and disease problems, see HGIC 2104, Flowering Bulb Insect Pests, HGIC 2049, Powdery Mildew, and HGIC 2100, Gray Mold (Botrytis Blight).
How to Grow
Most begonias grow well in partial shade with moist, well-drained soil containing plenty of organic matter. In general, begonias need bright light to flower well; however, some will burn if the light is too intense. Bronze-leaved wax begonias (Begonia x semperflorens-cultorum) grow better with full sun exposure than other types, whereas green-leaved cultivars are best planted in morning sun and afternoon shade to prevent sunscald on the leaves. When watering begonias, be sure not to water when the hot sun is hitting the foliage as the leaves will be scorched. Irrigation via drip tape, using a soaker hose, or watering early in the mornings, will reduce fungal disease problems.
Most begonias are not “heavy feeders;” therefore, apply a complete slow-release fertilizer formulated for annual flowers according to package instructions.
For information on how to prepare your landscape beds for planting begonias, see HGIC 1152, Growing Annuals.
Bedding varieties maintain a tidy and uniform habit and are ideal for small flowerbeds. Plants should be placed 12 inches apart for the best effect in the garden and somewhat closer in containers. Begonias look best when used in mass.
Species & Cultivars
The Begonia genus is a large and varied group, with more than 1,000 different species. The most common begonias for growing in southern landscapes are the fibrous-rooted semperflorens begonias (or wax begonias) and tuberous begonias. Most begonia species are tender in South Carolina, but the beautiful and perennial hardy begonia will grow throughout the state.
Wax Begonias (Begonia x semperflorens-cultorum): Few other annuals can beat the wax begonias for hardiness and continuous flowering throughout the summer. These begonias are not restricted to partial shade; they can be grown in full sun as well. Wax begonias with bronze foliage do better in the sun than green varieties. Wax begonias withstand drought and heat better than other begonias, although they prefer moist, well-drained, fertile soil.
Bushy plants, with shiny heart-shaped leaves of green, bronze-red, or mahogany are covered with small white, pink, rose, or red flowers.
Wax begonias can be grown from seed. Sow the tiny, dust-like seed indoors, on top of the growing medium, without covering, at 68 to 75° F. Start seed about 12 weeks before planting outdoors. Since the seed is tiny, it is often offered in a pelleted form to make handling the seed easier. Follow the seed packet instructions and use a sterile seed starting mix.
Set plants 6 to 8 inches apart in the garden after the danger of frost is past. Plants may also be started indoors from stem cuttings taken in the spring or fall.
- ‘Ambassador’ series has large flowers on compact, green-leafed plants.
- ‘Cocktail’ series is 6 to 8 inches tall with bronze foliage. The flower colors are ‘Brandy’ (pink), ‘Gin’ (rose-pink), ‘Rum’ (white with a rose-red edge), ‘Vodka’ (red), and ‘Whiskey’ (white).
- ‘Prelude Series’ hold up well through rain and heat. The compact plants have bright green foliage.
- ‘Pizzazz Series’ includes white, red, and pink cultivars. They are heavy blooming and grow 8 to 10 inches tall.
Hybrid Begonias (Begonia x hybrida) Modern breeding combines the wide variety found in the Begonia genome to achieve many different desirable characteristics.
- ‘Dragon Wing’ series is known for its long blooming period and will consistently flower from spring until frost without pause. It reliably reblooms because it is sterile and does not expend energy on producing seeds. They grow 2 to 3 feet tall, with tall arching canes and 5-inch long, glossy, deep green leaves and pink or red blooms. It will grow well in either sun or shade and prefers fertile, moist, but well-drained organic soil.
- ‘BabyWing’ series is a more compact, tidier version of ‘Dragon Wing’, reaching only 12 to 15 inches in height.
- ‘BIG’ series lives up to its name with plants reaching 36 inches tall. These begonias have either green or bronze foliage with red or rose-colored flowers.
Angel Wing Begonias (Begonia coccinea): Angel wing begonias, also called cane begonias, have thick, upright stems, fibrous roots, and pendant clusters of blooms in red, pink, or white. They can be grown as a houseplant or outdoors in partial shade during the summer. Their asymmetrical, wing-shape leaves are covered with white spots. Their leaves will lose the dot pattern and eventually scorch if they are exposed to too much sun.
Tuberous Begonias (Begonia x tuberhybrida): Tuberous begonias grow best in partial shade. The plants need frequent watering and light fertilization, but an excess of either causes flower bud drop. Tuberous begonias grow best in the upper Piedmont and mountain areas of South Carolina. They do poorly in very hot and humid parts of the state.
Tuberous begonias have 2- to 4-inch wide flowers in white, yellow, orange, rose, red, and pink. They are available either in upright varieties or with trailing stems 12 to 18 inches long. The trailing types are nice to plant in hanging baskets.
Tuberous begonias must be dug up and replanted each year because they will not survive the winter cold. Dig tubers before the first frost. Cut tops back to within a couple of inches of the tubers. After drying, pack the tubers in cardboard boxes between layers of vermiculite, peat moss, or wood shavings and store at 45 to 55° F.
Start tuberous begonias in early spring by setting tubers into shallow flats. Keep out of direct sunlight. When the roots are established and shoots are about 1 or 2 inches high, move them to pots 4 to 6 inches wide. When all danger of frost has passed, move them outdoors to a partially shaded location.
Tuberous begonias can also be grown from seed indoors. However, they take a few weeks longer to mature than wax begonias. They should be started from seed as much as 14 to 16 weeks before they will be ready to be planted out in the landscape.
- ‘Illumination’ series is popular for hanging baskets and has double blooms in a variety of colors.
- ‘Non-stop Series’ are compact and small-flowered multiflora types. They are more heat-tolerant than other tuberous begonias and will flower longer. This type is best suited to growing in the South.
Begonia boliviensis (Begonia boliviensis): This species features graceful arches of dangling blooms that appear like elongated stars. It is best in hanging baskets, window boxes, or containers and has been selected in a variety of bright colors. The original species is a vibrant scarlet/orange. It is a parent in the hybrid crosses that led to the tuberous begonias.
Hardy Begonia (Begonia grandis): This is a superb southern heirloom perennial that has been passed from gardener to gardener. They grow best with rich, moist soils in partial shade.
The hardy begonia reaches 2 to 3 feet in height. This begonia will form a large mass in the landscape; therefore, be sure to give it plenty of space as it will spread. Small, pink flowers bloom in drooping clusters above the leaves in late summer. The large angel wing-shaped leaves are backed in glowing red. They are especially lovely when planted where the late, low afternoon sun will shine through the leaves. Tiny bulb-like tubers that appear at the leaf joints in late summer can be used to increase stock or to share with a neighbor. Plants will die back to the ground in winter and are hardy to USDA Hardiness Zone 7.
Rex Begonias (Begonia rex): Rex begonias are not grown for their flowers, but rather for their beautiful leaves. The leaves can be a kaleidoscope of colors that range in hues of green, red, pink, silver, gray, lavender, and a shade of maroon, so deep that it appears black. These spectacular begonias grow best indoors or in containers placed in partial shade. Rex begonias are rhizomatous plants and are propagated from leaf or stem cuttings.
- ‘Merry Christmas’ grows 10 to 12 inches tall with smooth red and green leaves shaped like lopsided hearts.
- ‘Fireworks’ grows 6 to 14 inches tall with a margin and center burst of maroon on silver wing-shaped leaves.
- ‘Helen Teupel’ grows to 12 inches tall with pointed, sharply lobed leaves that are purplish-red brushed with pink and silver.
For more information about growing begonias indoors, see HGIC 1552, Growing Begonias Indoors.
Originally published 03/99