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Writer's pictureCasey Lester

The Silent Menace: Mulch Volcanoes and Their Impact on Cincinnati's Trees

Updated: May 17

In the Cincinnati Tri-State Area, amidst its bustling streets and charming neighborhoods, lies a silent menace that often goes unnoticed: mulch volcanoes. While the term "volcano" might conjure images of fiery eruptions in far-off lands, these insidious mounds of mulch pose a very real threat to the health and longevity of our trees.

Mulch Volcano

What exactly are mulch volcanoes? Imagine walking through a park or your neighborhood and noticing a heap of mulch piled up against the trunk of a tree, resembling the shape of a volcano. This common landscaping practice, known as "volcano mulching," involves stacking mulch in a cone-like shape around the base of a tree, often reaching several inches or even feet high.


At first glance, mulch volcanoes may seem harmless or even beneficial, as mulch is commonly used to suppress weeds, retain moisture, and improve soil quality. However, the reality is quite the opposite. Mulch volcanoes can have detrimental effects on tree health and vitality.


Damaged trunk

One of the primary concerns associated with mulch volcanoes is the potential for moisture accumulation and root suffocation. When mulch is piled up against the trunk of a tree, it retains water in areas where excessive moisture is not beneficial and can also create a barrier that restricts air from reaching the trunk. As a result, the roots may become waterlogged, leading to root rot and other moisture-related issues. Additionally, the excessive moisture trapped within the mulch can attract pests and pathogens, further jeopardizing the tree's well-being. Soil-borne tree diseases such as armillaria root rot and phytophthora root rot can also be exacerbated by the presence of mulch volcanoes.


Furthermore, mulch volcanoes can also cause structural instability in trees. As the mulch accumulates around the base of the trunk, it creates a mound that can put pressure on the tree's bark and cambium layer. Over time, this pressure can lead to bark damage, trunk decay, root rot, and even structural failure.


Girdling Roots

In an effort to survive, a tree may grow adventitious roots that often lead to girdling roots. This can help the tree survive in the short term, but will eventually girdle the tree trunk, causing premature fatality.







Proper Mulching

So, what is the solution to this silent menace? The key lies in proper mulching practices. Instead of piling mulch up against the trunk of a tree, it is essential to create a mulch "donut" or ring around the base of the tree, leaving a gap between the mulch and the trunk. This method, known as "proper mulching," allows for adequate air and water circulation to the tree's roots while still reaping the benefits of mulch, such as weed suppression and moisture retention.


Tree Planting

Proper mulching not only benefits the health of individual trees but also contributes to the overall health and resilience of Cincinnati's forest. By educating ourselves and others about the dangers of mulch volcanoes and promoting responsible mulching practices, we can help preserve and protect the invaluable natural resources that grace our cityscape.


So, the next time you find yourself tending to your garden or strolling through a local park, remember the importance of proper mulching and say no to mulch volcanoes. Your trees will thank you, and Cincinnati's forest will continue to thrive for generations to come.




Our team at Gregory Forrest Lester, Inc. is dedicated to meeting all your tree planting and landscaping needs in the Cincinnati Tri-state area. Together, let's ensure that mulch volcanoes don't threaten the health of our trees. With our expertise and commitment to sustainable practices, we strive to keep Cincinnati's landscape thriving and free from such harmful practices.

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