Begonia (Semperflorens Cultorum Group)
Common Name: begonia 
Type: Herbaceous perennial
Family: Begoniaceae
Zone: 10 to 11
Height: 0.50 to 1.00 feet
Spread: 0.50 to 1.00 feet
Bloom Time: June to frost
Bloom Description: White, pink, red, bicolor
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Annual
Flower: Showy
Tolerate: Rabbit, Dry Soil, Black Walnut

Culture

Tender perennial that is winter hardy to USDA Zones 10-11. In St. Louis, it is grown as an annual. It is noted for its tolerance to hot and humid summers. It is easily grown in average to moderately fertile, moist, well-drained soils in full sun to part shade. Prefers sun dappled part shade and a good mulch in hot summer climates such as St. Louis. Bronze-leaved varieties are more tolerant of full sun. Plants tolerate considerable shade, but are generally less floriferous therein. Plants are best with consistent moisture throughout the growing season, but tolerate periods of drought due to their thick and waxy leaves which help minimize water loss in hot weather. Start seeds indoors 6-8 weeks before last frost date, purchase starter plants or take cuttings from overwintered plants. Set plants out after last frost date. Space plants well (8” for dwarfs and 12” for taller ones) to promote good air circulation and to reduce potential fungal disease problems. Container plants may be cut back in fall and overwintered indoors a cool location with reduced watering. Propagation from seed can be difficult due to the small size of the seed, and seed should not be sown directly in the garden.

Noteworthy Characteristics

Begonia is a genus of about 1,300 species of annuals, perennials, shrubs and climbers. Most have fleshy stems. Some produce underground tubers or rhizomes. They are grown for their showy flower or colorful leaves; some for both. Begonias can be divided into 7 informal groups by growth habit: cane-like, rex-cultorum, rhizomatous, semperflorens, tuberous, trailing or scandent, thick-stemmed and shrub-like.

Semperflorens Cultorum Group, often called wax begonia, is an extremely popular garden annual. It is a compact, bushy, mounded, fibrous-rooted plant that features fleshy stems, waxy dark green to bronze leaves and loose clusters (cymes) of single or double flowers in shades of white, pink or red plus bicolor versions thereof. Flowers reliably bloom throughout the growing season (May to October). Dwarf varieties grow to 6-8” tall and taller varieties grow to 10-12” tall.

Genus name honors Michael Begon (1638-1710), Governor of French Canada.

Group name means ever-blooming plants of cultivated lands and gardens.

Problems

Susceptible to powdery mildew, botrytis, and stem rot, especially in humid conditions with poor air circulation. Watch for mealybugs and thrips.

Uses

Suitable for massing in beds, borders, and as an edger. Use in containers and window boxes.