Did you know that incorrect placement of mulch under and around your trees can actually be bad for them?
Here are some tips for placing mulch around a tree:
- Make sure the mulch is at least 10-20 centimetres away from the trunk of the tree, and definitely not touching the trunk!
- Ideally use forest mulch that has been aged by at least 1 to 2 months.
- Spread the mulch around the tree into the surrounding landscape as wide as you like, tapering out to the ground level at the edge of the ring.
How does too much mulch, or “volcano mulching” harm or kill trees?
Too much mulch depth restricts soil oxygen exchange with the tree and its roots. Mulching against the trunk of the tree also creates a moist environment which promotes cracking of the bark, creating an entry point for insects and fungal growth. Mulch around the base of a young tree may promote the roots to grow into the mound of mulch and not into the surrounding soil.
That said, mulch has many benefits:
- Moderates the temperature of the root zone creating a ripe ecosystem for beneficial micro-organisms and other helpful critters.
- Encourages the conservation of moisture in the soil by reducing surface evaporation – this can be an important factor here in Brisbane.
- It can help control weeds.
- Prevents the soil from crusting over, allowing water to penetrate.
- Improves soil aeration, soil structure (less soil compaction) and drainage.