The hardy begonia (Begonia grandis) provides the elusive mid- to late-summer flowers that woodland gardens often lack, since many shade-garden perennials bloom in spring and offer summer interest through their foliage. Hardy begonia is interesting in both flower and leaf, and it has an elegant habit that complements the shade garden's mounding forms.
Common name: Hardy begonia
Botanical name: Begonia grandis
Exposure: Part shade to full shade
Flowers: From midsummer into fall, small, soft or bright pink flowers appear in loose clusters on branched stems from midsummer through autumn.
Foliage: The leaves are large, heart-shaped and asymmetrical, with toothed edges and red veining across a medium green background. The underside of the leaves has a red to bronze tint.
Size and habit: This herbaceous perennial reaches about two feet tall and wide, with an upright mounding habit.
Origin: The species Begonia grandis is native to China and Japan.
How to grow it: Plant hardy begonia in part to full shade and rich, woodsy soil. It requires even moisture, but good drainage is important; don't try to grow it in a wet spot. Deadheading the flowers can help prolong the bloom.
This begonia forms small bulbils where a leaf stem meets the main stem. The bulbils fall to the ground when the plant goes dormant in fall, and they may sprout the following spring, so that over time the population of Begonia grandis increases.
Begonia grandis is hardy in USDA Zones 6 through 9, but it may benefit from a winter mulch to help its roots survive the Zone 6 winter. A deep mulch of fine tree leaves can serve this purpose while also building the rich soil that Begonia grandis thrives in. Like other late bloomers, it may be slow to resume growth in spring, so be careful if planting near it.
Image credits, top to bottom: Cory, CC BY-SA 3.0; El Funcionario - Own work, CC BY-SA 4.0; manuel m. v./CC BY 2.0
