Begonia 'Boomer' is a rhizomatous hybrid Begonia with thick stems and beautifully textured leaves that can grow to impressive sizes.
As the plant matures, the deep red/burgundy edge to the leaves will darken.
They prefer a bright, but shaded position in your home. Not in direct sunlight, otherwise the leaves may burn.
Water semi-frequently and make sure it never dries out completely, at the same time ensuring it also doesn't stay too wet.