Four fire engines and around 25 firefighters were called to a fire at a garden centre on Sandpiper Road in Cheam.
A single-storey timber building was destroyed by the fire and a small part of another single-storey timber building was damaged. There were no reports of any injuries.
The Brigade was called at 0203 and the fire was under control by 0332. Fire engines from Sutton, Wimbledon and New Malden fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.