When I was a kid growing up in rural Indiana, everyone burned their leaves in the fall. No bagging or mulching, just rake them into a long windrow and set them ablaze. I distinctly remember the first time I was allowed by my late Grandpa Mac to actually tend the fire, when he showed me how you had to continually churn the leaves in order to get them all to burn.
Because they were so tightly compacted, oxygen couldn’t feed the flames below the surface. I marveled at the way the interior of the pile seemed untouched by a blaze that was almost too hot to approach and I learned the value turning things over.