Firefighters were called to a 600 tonne stack of tree cuttings and bark chippings alight on The Ridgeway in Enfield on Sunday morning.
Four fire engines, 21 firefighters and officers from Enfield, Southgate and Edmonton fire stations attended the blaze.
The Brigade was called at 10.08 and the fire was under control by 1208. The cause of the fire is under investigation.