The Fairmount Fire Company No. 1 in Long Valley responded to the blaze in the woods near Old Turnpike and Wildwood Roads in Tewksbury Township on Friday, April 15, the department said.
Crews found the lawnmower fully engulfed in flames that had spread to a compost pile and a quarter-acre of woods nearby.
The department remained at the scene for about an hour and a half to fully extinguish the blaze.
Assisting agencies include fire companies in Oldwick and Pottersville, as well as the NJ Forest Fire Service.
Scroll down to view additional photos from the scene.
The cause of the fire was not immediately clear.
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