Mulch can damage trees

Too much mulch applied over the root ball or resting against the trunk (see right photos) can cause problems for trees. Roots often grow up and into the mulch causing stem girdling roots which can kill trees (lower photo). This is especially troublesome on trees planted within the last 10 to 20 years. In addition to causing problems described below, mulch can also hide decay and dead spots on the lower trunk and major roots. Decay in this portion of the tree can cause the tree to become unstable. Keep mulch about 12 to 18 inches from the trunk for any size of tree.	Mulch should not be piled against the trunk (above) because roots may grow there (below) and girdle the trunk.
Latest research on mulch affect on trees Mulch on root ball intercepts water, causes problems Mulch near trunk causes stem girdling roots/ treatment Mulch close to trunk causes decline Mulch close to trunk causes tree death Good vs. bad
Appropriate mulching (3" depth and none on root ball) shown below

• Trees
  • Urban design |
  • Site |
  • Selection |
  • Nursery |
  • Planting |
  • Pruning |
  • Health |
  • Species |
  • Roots |
  • Structure |
  • Biology |
  • Storms |
  • Power lines
• Shrubs
  • Selection |
  • Production |
  • Planting |
  • Maintenance |
  • Species
• Groundcover
  • Selection |
  • Production |
  • Maintenance
• Palms
• PowerPoints
• Fact sheets
• Research abstracts
• Landscape designs
• Other resources
• Site index