In cold areas, start the tubers indoors about 6 weeks before you anticipate the last frost. Plant the tuber in potting soil, round side down, about 2-3 cm below the surface. Water well and then keep the soil moist but not soggy. Keep in a warm, semi-shady area. When all danger of frost has passed, transplant outdoors being careful not to disturb the roots.Keep in a warm, semi-shady area. When all danger of frost has passed, transplant outdoors being careful not to disturb the roots.
In the garden, begonias
need rich, porous, well-drained soil and shelter from wind. Space 30 cm apart in shade or partial shade. Keep the soil evenly moist and fertilize at least once a month. Tuberous begonias
should be dug and immediately given a bath after they are lifted. They should be stored over the winter in shallow, open trays. If there may be mice or other rodents, place a wire covering over the open trays. Hardy in Zone 10.