Unlike the more common annual begonia, the hardy begonia is a perennial that grows well in USDA gardening zone 6 and higher. It has pink or white flowers and large red-veined leaves. It blooms from mid-summer until fall frost and then returns with foliage the following spring. Hardy begonia is propagated from bulbils. These are small bulb-like structures that form in the fall at the juncture between the stem and a leaf. Each plant produces several bulbils, so you can grow as many new plants as you desire.
Fill a 4 to 6 inch diameter pot with quality potting soil. Combine 1 part peat moss and 1 part sterilized compost to make your own potting mix. Sow the bulbil ½ inch beneath the soil surface.
Keep the soil moist but not soaking wet at all times. Water as necessary to maintain moisture when the top of the soil begins to dry.
Transplant outside in spring once foliage begins growing. Prepare a well draining garden bed in full to partial shade. Lay a 2 inch layer of compost over the bed and till it in to a 10 inch depth to aid drainage and soil nutrition.
Plant the hardy begonia to the same depth it was at in the pot. Space plants 12 inches apart in staggered rows.
Lay a 2 inch layer of organic mulch over the bed to preserve soil moisture. Water only during extended dry periods. Dress with fresh compost each spring.