Mulch: how deep, what kind, and the mistake that kills shrubs

Mulch is the cheapest thing that makes a property look maintained, and the easiest to overdo to the point of damage.

Depth

Two to three inches. Less and weeds come through; more and water struggles to reach the soil while roots start growing up into the mulch layer.

Never against the stem

Mulch piled against a trunk holds moisture on bark that is not designed to stay wet. It invites rot and rodents. Pull it back a hand's width from every stem.

Hardwood, cedar or dyed

Natural hardwood breaks down fastest and feeds the soil. Cedar lasts longer and holds colour. Dyed mulch keeps colour longest; quality varies with the source material, so it is worth asking what the base wood is.

Refresh, do not rebuild

Every spring, fluff what is there and top up thin areas. Adding a full new layer every year is how beds end up six inches deep and slowly suffocating.

Beds and mulch