Mulch Myths Debunked: Volcanoes, Acidity, and Tiny Rings

Myth 1: Piling Mulch High Is Good

“Volcano mulching” (12–24 inches against the trunk) traps moisture, inviting decay fungi and voles. Always pull mulch back 6 inches from trunks and keep total depth ≤6 inches.

Myth 2: Pine Straw Acidifies Soil

Pine needles, oak leaves, cedar—all decompose into tiny amounts of organic acids, far too little to shift soil pH. Use pine straw anywhere; it’s a myth that it “makes soil acidic.”

Myth 3: A Small Ring Around a Tree Is Enough

Tree roots extend far beyond the drip line. A 3-ft ring around a 20-ft tree protects only the mower, not the roots. Mulch to the branch tips and beyond, especially for shallow-rooted species like dogwood.