Depends - if they're F1 hybrids, you either won't get any seed or they'll be sterile.

For the past two years I have been buying in the plugs and planting them up. I just want to save money next year by doing it myself. I never looked inside my baskets last year after the flowers have died in October to see if they developed tubers or not. I will have to see this year. Can you explain what you mean by F1 hybrids? How does this work? Thanking you in advance.

F1 hybrids (you may or may not have that information on the labels) are really overbred monsters - breeders cross and cross and cross to get certain forms or colours, and inevitably end up with something that can't breed all by itself, basically! There are many different types of Begonias too - some are just bedding begonias with ordinary roots, others have corms - I don't know which ones you're growing. If you see any seed, collect it and give it a shot.

Thanks for that info (you always learn things when gardening) I will try and collect seeds this year (pod willing).

Nice one,"pod willing", like it...