Volcano Trees
The intention is right, but the end result may not be helpful.
Volcano trees are popping up all over Franklin Park. It’s been trending! There is likely a volcano tree not too far from you…or even in your own yard! ‘Volcano’ trees are trees with mulch piled too high around the trunk, which could be a problem for your new, expensive trees or your old majestic ones! Mulch piled high around the tree base has become an aesthetic, somewhat like leafless lawns (but more on that later!). Often, it’s applied by landscapers who don’t know any better.
Mulch, appropriately applied, provides services for the trees and the environment by:
maintaining soil moisture and temperature in both warm and cold weather.
reducing watering needs and controlling weeds,
improving soil fertility and inhibiting plant disease,
saving trees from damage caused by power tools, and
providing a uniform, well-cared for look
In a natural, forest environment, trees are rooted in rich, organic, well-aerated soil that has been built up through layers of leaf decay. This soil is rich, and it takes decades to create. Urban soil is harsher, especially on newly developed land where there is often fill material, little or no topsoil, and large fluctuations in temperature and moisture.
Trees in urban landscapes can often be stressed and have shorter lifespans, but proper mulching should help lower the stresses. Improper mulching could have the opposite effect.
Two to four inches of mulch spread around the base of the tree as broadly as possible protects the fine roots close to the surface. These roots absorb water and nutrients. Mulch helps trees retain moisture, regulate temperature, and it improves soil structure and oxygen levels.
Too Mulch of a good thing…
Many North American landscapers over mulch, and this can damage trees by leading to excess moisture in the root zone. The result could be root rot, an invitation to insects and diseases, habitat for rodents, or blocking the free passage of air and water. If your landscaper has created a volcano tree in your yard, you can easily remedy it by scooping the mulch away from the trunk. Make sure you remove enough so that you see the root “flare”—the big roots that emerge at the bottom of the trunk.
Commercial mulches are available in many forms. Application of just 2 to 4 inches is a great way to help maintain the health of your trees. And, as stated, too mulch can do damage.
But the best mulch is the tree’s own leaves! Not to mention that it’s free! Consider creating a berm around your tree. It could be made of brick, light fencing material, or decorative stones. Then let the leaves fall within this boundary or rake leaves in. This natural layer will not only protect the tree but will also fertilize and replenish the soil and provide habitat for small creatures that depend on this cycle.
If there is just one take-away, let it be that mulch built up around the base of your beloved trees could be killing them. Pull it back to give the tree space to breathe and somewhere for rainfall to reach its roots!