Tree Mulching — Why and How

Mulching is an essential step in caring for your newly planted tree!

A mulch ring around the base of a tree provides many benefits, including:

  • A barrier from damage caused by lawnmowers and weed eaters
  • Insulation, providing a buffer from temperature extremes
  • Water retention, helping to keep roots moist
  • Nutrition — as the mulch decomposes, it slowly feeds the tree roots
  • Suppression of weeds


How to properly mulch a tree

The easiest way to remember how to mulch a tree is to follow the 3-3-3 rule:

3 feet wide, 3 inches deep, and 3 inches away from the trunk

Photo courtesy of Arbor Day Foundation


What To Avoid

When mulching, think donut rather than volcano. Keep it shallow, and avoid having mulch touching the trunk of the tree. Volcano mulching is one of the biggest threats to tree health!

Photo courtesy of The Morton Arboretum

Mulch piled high around the tree trunk can result in a number of problems, including:

  • Water retention around the trunk, causing disease and decay (and ultimately tree death!)
  • Damage from insects and rodents
  • Smothered roots — too much mulch inhibits necessary air flow necessary for growth
  • Causing girdling roots, which essentially ‘choke’ the tree
  • Wasting your hard earned dollars! Not only are you using more mulch than needed, but the money invested in your tree will sadly be lost if the tree does not survive.

Read more: Ditch the mulch volcanoes; they can kill your trees | The Courier-Journal