Fallen Branches And Leaves Replace Chemicals: Layered Method Turns Waste Into Super-SoilPiles of pruned branches and bags of fallen leaves are often treated as waste to be hauled away. If you interleave fine twigs with leaves, the pile develops a kind of skeleton that lets microorganisms work faster." Wood Chips as Biofuel for Warm BedsLarge woody debris that breaks down slowly in its natural form can be chipped. To avoid this, drench woody residues with a urea solution beforehand or let them age in the compost pile. Wood chips are ideal for shrubs, perennial flowers and tree root circles.