Four fire engines and 21 firefighters and officers were called to a fire at a range of sheds on allotments on Sutton Lane in Hounslow.
A range of sheds has been destroyed by fire. Three people left the allotments' area before the arrival of the Brigade.
The Brigade was called at 0802 and the fire was under control at 0904. Fire crews from Heston and Feltham fire stations attended the scene.
The cause of the fire is under investigation.