Scientific: Begonia cucullata (Synonym: Begonia semperflorens)
Common: wax begonia
Family: Begoniaceae
Origin: South American countries of Argentina, Brazil, Paraguay, and Uruguay.
Invasive Alert: Naturalized in Florida and Hawaii.
Pronounciation: Be-GON-ee-a sem-per-FLOR-ens
Hardiness zones
Sunset All (as annual or tender perennial depending on climate)
USDA 1-9 (annual), 10-11 (tender perennial)
Landscape Use: Depending on exposure and microclimate wax begonia is a tender annual to short-lived perennial garden herb in lower desert regions, entry ways, containers or hanging baskets for patios, indoor atriums with bright natural lighting. Best used in close approximation to human activity.
Form & Character: Wax begonia is short and clumping with a rather formal appearance, neat and tidy, delicate, colorful, bright and cheerful.
Growth Habit: Herbaceous, short-lived perennial that is mostly treated as an annual in Phoenix landscape gardens. Slowly clumps and spreads. Height is generally under 18 inches.
Foliage/Texture: Cordate to orbicular succulent leaves, 1 to 2 inches in diameter with distinct palmate venation, green, bronze to deep wine red, adaxially surfaces have a thick cuticular wax layer, margins smooth and entire to crenate; medium texture.
Flowers & Fruits: Begonias have separate male and female flowers, which are borne on the same plant. Female flowers have a seed capsule below their petals, male flowers do not. Flowers are either single (fertile) or double (sterile), ranging in warm colors from white to red. Fruits have three wings.
Seasonal Color: Flowers nearly continuously.
Temperature: Wax begonia is tolerant of summer heat when grown within a Phoenix mesic garden setting with an organic mulch; however, wax begonia is intolerant of freezing temperatures below 32oF. The cardinal optimum temperature for wax begonia growth and culture is around 65oF.
Light: In Phoenix, partial to full shade, intolerant of full sun locations.
Soil: Easily salt damaged. Does best in low salinity, well-drained soils that are heavily amended with organic matter; ergo, rich garden soil conditions are best.
Watering: Regular irrigations in desert areas especially during the Phoenix (cough...cough) 'warm' season.
Pruning: None
Propagation: Seed, but short, stem cuttings are especially easy to root.
Disease and Pests: None
Additional comments: Wax begonia is one of the most widely planted bedding plants in the western world. Deer resistant - an important bedding plant tip for you northern Arizona dwellers in Prescott, Payson, Show Low, Williams, and Flagstaff.
Taxonomic tidbits: The genus Begonia is very diverse (over 900 species), is of great horticultural interest amongst collectors and breeders, and is widely cultivated around the world. Check out the American Begonia Society.