Hardy begonia (Begonia grandis) is an herbaceous perennial flowering plant native to Southern China, Japan, and Malaysia. It is a member of the Begonia (Begoniaceae) family (USDA hardiness zones 6-9). From summer into early fall, hardy begonia displays loose arching clusters of bright pink fragrant blooms. It is monoecious, e.g. both male and female flowers are on the same plant. Tuberous-rooted begonias grow a 2-feet tall; they form a bushy mound of foliage on branching stems.

Leaves are bright green and heart shaped. Dangling clusters of delicately fragrant pink (or white) flowers. Hardy begonias can be planted in beds with spring bulbs. Hardy begonias are late comers, e.g. shoots don’t emerge until after spring bulbs have faded. Leaf undersides are brightly red and are especially beautiful, particularly planted in containers and backlit by the late afternoon sun.

Hardy begonias are at their best in shady borders, woodland gardens, or along walkways. They grow best in moist, humus-rich, well-drained soils in part shade to full shade. Do not allow the soil to dry out. Apply a heavy winter mulch where plants are marginally winter hardy in zone 5b. Deadhead flowers to extend their blooming interval.

Begonia leaves turn yellow gradually in the autumn. At the same time, bulbils form in the leaf axils. These tiny asexual formations about the size of a small pea drop to the ground in fall and sprout the following spring. Plants may also self-seed. After a couple of years hardy begonias gradually become a small colony in the garden.

Hardy begonia mixes well with assorted small hostas, astilbes, and ferns in shade or woodland gardens, in shaded border, and in containers. To extend the blooming period, deadhead expired flowers. Disease and insect problems are minimal.

Cultivars

‘Alba’ producespure white flowers with yellow centers on bright pink stems; petals age to a pale pink.

‘Simsii’– hardy begonia is white-flowering cultivar hardy to zone 5b.

‘Torsa’ – develops huge leaves. In year one, leaves reach 10-12 inches long and attain their full 20-24 inches in year 2, plus showy red ribs down the backside.