Most garden beds need three inches of mulch. Not one. Not four. Three.
One inch blocks some annual weeds but dries out fast. Two inches saves water but still lets persistent weeds through. Four inches insulates roots in winter — but traps moisture against stems and causes rot in actively growing beds.
Three inches is where everything works at once. Weeds stop germinating through it. The soil underneath stays dark and moist between waterings. And the bottom layer is constantly decomposing — feeding organic matter into the soil while the top layer is still suppressing weeds.
The mulch is building your soil and protecting it at the same time.
The one rule at any depth:
– Pull mulch back an inch or two from every stem. Mulch touching bark holds moisture against it around the clock — that’s how collar rot starts. The bare circle around each stem isn’t laziness, it’s the whole point
Best mulch by use: straw for vegetable beds (light, cheap, breaks down in one season), wood chips for perennials and paths (lasts longer), shredded leaves for free soil feeding (decomposes fastest).
Three inches. Pulled back from stems. That’s the entire system