Stop the Mulch Volcano! Why Mulch Mounds Are Harming Your Trees

It’s a common sight in well-meaning landscapes—mulch piled high like a volcano around the base of a tree. While it might look tidy, this practice can actually harm your trees.

Known as “mulch mounding” or “volcano mulching,” this technique traps moisture against the trunk, leading to rot, disease, and pest issues. It also encourages roots to grow upward in search of oxygen, potentially girdling the tree and strangling its growth over time.

The Right Way to Mulch:

• Keep mulch 2–4 inches deep—never higher.

• Pull mulch back from the trunk, leaving a 3–6 inch gap.

• Extend mulch out to the tree’s drip line if possible.

Mulch can be a great tool for water retention and weed control, but only when used correctly. Protect your trees by skipping the volcano and opting for a healthy, donut-shaped mulch ring instead!

For more tips on proper tree care and planting practices, check out these resources from the Arbor Day Foundation:

• How to Mulch Trees the Right Way

• Tree Care Tips & Techniques

• Avoiding Common Tree Planting Mistakes

Let’s keep our trees healthy for generations to come—ditch the mulch mound!