Tuberous begonias in autumn. How to prune begonias. An individual approach to each begonia.
If a tuberous begonia's trunk is bare, it's ready to go dormant and spend the winter. This type of begonia should definitely be pruned back to a stump. However, these stumps shouldn't be broken off; they should be allowed to fall off on their own. Once the stumps fall off, the tubers should be removed from the soil, dried, and stored in dry peat in a cool place. If the begonia has sprouted new shoots and isn't yet dormant, prune off all old shoots that have bloomed, remove all old leaves and stems, and leave only the new growth. With proper care, fertilizing, and lighting, the begonia may not go dormant. It may continue to bloom for some time. If the begonia's leaves are still green and it's blooming, you should hold off on pruning for a while.