Perennial begonias come in many varieties, from wax begonias to tuberous root begonias. Begonias are grown in containers, garden beds, and due to the short height they also work well as an edging plant. Begonias benefit from pruning and in some instances being cut back completely. This encourages fresh blooms and keeps the plants bushy and full. When cutting back the proper method must be followed, otherwise irreparable damage may be done to the plant or it may take it longer to return to full bloom.
Pinch off the growing tips of new begonia plantings in spring. Pinch off the top 1 inch of each stem to encourage branching and help control size.
Cut back any stems and shoots that grow longer than the rest of the plant throughout the growing season. Use sharp shears and cut them off to the same height as the bulk of the begonia plant.
Cut back tuberous begonia plants in fall after the foliage begins to yellow and die back. Cut down to within 3 inches of the ground.
Cut back any begonia that has become overgrown or is blooming poorly. Remove any hard, woody stems and cut back fresh green growth to a 6 inch height. Leave at least two leaves on each stem or it won't survive.
Discard of any removed plant matter from the begonia bed immediately. Botrytis blight and other diseases are spread via the removed vegetation.