University of Maryland Extension


Back to Excessive Mulch

handfull of mulch
Photo: Andrew Koeser, International Society of Arboriculture, 

Mulching to reduce weeds, conserve soil moisture, and minimize soil erosion is a standard horticulture practice. Plants that are not mulched correctly can experience problems, decline, and even die from too much mulch piled on root systems. The following are resources to help mulch your garden correctly:

(PDF) Mulching for a Healthy Landscape (Virginia Tech publication) – Provides a description of organic and inorganic mulches and how to mulch.

Mulch – (Clemson Cooperative Extension) - Benefits of mulching, mulch materials, how to calculate  the amount of mulch needed, and mulch problems.

Wood Chip Mulch: Landscape Boon or Bane? - Washington State University

Artillery Fungus FAQ's - Penn State Extension (see photo below)

Examples of correctly mulched trees

correctly mulched tree

tree that has the correct amount of mulch

Additional Resource

Vegetable garden weed control


(PDF) HG 803 Mulch Problems: Commercial Landscape Series
ARG97-27 - Mulch - What's Growing in My Landscape Mulch?

to much mulch around the base of a tree
Too much mulch (mulch volcano)
mulch around the base of a tree
Do not let mulch touch the base of trees
tiny black dots of artillery fungus
Artillery fungus is attracted to light
colored objects
bird's nest fungi in mulch
Bird's nest fungi
Maintained by the IET Department of the College of Agriculture and Natural Resources. © 2019. Web Accessibility