Now is a good time to take cuttings from your favourite Begonias. It is a safe way to increase your stock.
With a sharp knife carefully make two downward cuts to remove the side shoot from between the leaf stem and the main stem of your plant.
Plant the cuttings in compost and place in a propagator or a pot with a plastic bag, but be sure to wipe away droplets of moisture each day.

The picture shows a good example of a Begonia cutting. .