Common Name: hardy begonia
Type: Herbaceous perennial
Family: Begoniaceae
Zone: 6 to 9
Height: 1.50 to 2.00 feet
Spread: 1.00 to 1.50 feet
Bloom Time: July to September
Bloom Description: White
Sun: Part shade to full shade
Water: Medium to wet
Maintenance: Medium
Suggested Use: Naturalize
Flower: Showy
Tolerate: Heavy Shade, Black Walnut
Culture
Best grown in moist, organically rich, well-drained soils in part shade to full shade. Soils should not be allowed to dry out. Winter mulch is advisable in the St. Louis area where plants are not reliably winter hardy. Deadhead flowers to extend bloom period. Self-propagates by tiny bulblets which form in the leaf axils autumn and drop to the ground. Bulblets may also be harvested from the leaf axils and planted as desired. New season growth is usually late to appear.
Noteworthy Characteristics
Begonia grandis, commonly called hardy begonia, is the only species of Begonia that is winter hardy to the St. Louis area. It is a monoecious, tuberous-rooted, clump-forming perennial that typically forms a bushy mound of foliage to 2’ tall on branching stems. Large, obliquely ovate leaves (to 4” long) with cordate bases are medium to olive green above and reddish green with red veining beneath. Male and female pale pink flowers (to 1” across) bloom in pendent clusters (dichotomous cymes) from July to early fall.
Var. evansiana is very similar to the species and some taxonomist include it within the speices. Others have classified it as its own species, B. evansiana
Genus name honors Michael Begon (1638-1710), Governor of French Canada.
Specific epithet means big or showy.
'Alba' is a white-flowered form.
Problems
No serious insect or disease problems. Winter hardiness is a concern in St. Louis.
Uses
Good late summer flowering shade plant which mixes well with hostas and ferns in the shade garden, woodland garden or shaded border.