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Urban forestry expert warns against common mulching method that could be killing your trees: ‘When you mulch the tree, you run into serious issues’

“Tree roots will always find the most delicious, nutritious parts of the soil.”

"Tree roots will always find the most delicious, nutritious parts of the soil."

Photo Credit: iStock

Many well-meaning homeowners are making a fatal mistake when fertilizing their trees, but this nature-loving TikToker will help you avoid it.

Urban forestry TikToker Alexa Rice (@alexachristinarice) posted a video about a practice she called “volcano mulching.” Volcano mulching is piling up mulch directly against the tree trunk to make a volcano-shaped mound. 

“It’s the d*** devil,” she says. “Let me tell you why.”

@alexachristinarice Please don’t mulch your trees instead of the soil around it. It hurts my feelings 🥺 Have you seen volcano mulching in your neighborhood? #CapCut #mulchvolcano #mulch #mulching #urbanenvironment #intersectionalenvironmentalist #urbanforest #urbanforestry #trees #treeservice #planttrees #urbanlandscape #urbanplanning ♬ original sound – Alexa | Beauty for Trees 🌳💖

As Rice explains, where mulch goes, the tree’s roots will follow. 

“When you mulch the tree, you run into serious issues such as girdling, aka tree asphyxiation,” she says, showing a picture of a tree that has its own roots wrapped tightly around the base of its trunk.

This dangerous condition is the result of the tree’s natural behavior gone wrong. 

“Tree roots will always find the most delicious, nutritious parts of the soil,” Rice says. “If the mulch is piled high like that volcano shape, those roots will wrap themselves around the tree to really get into the heart of that mulch, which suffocates the tree, which completely prevents the tree from sucking up those nutrients, which ultimately kills the tree.”

She also says that volcano mulching can harm the health of the roots and introduce diseases and stem rot to the tree. According to Rice, this is an easy mistake to make while trying to care for a tree. 

“Typically, mulching is very good for a tree,” she says. “It provides the tree with many nutrients it might otherwise not get on its own.” Indeed, mulching can turn a lifeless yard into one bursting with greenery, as this Redditor demonstrated.

“But volcano mulching does the exact opposite,” Rice adds.

The cure?

“Mulch the soil, not the tree,” says Rice. 

She then provides a diagram with mulch placed in a ring around the tree, leaving a clear well around the base of the trunk. For the mulch, you can use wood chips or other organic material, but the best way to do it for free is with autumn leaves — which also keep trash out of landfills. 

Commenters were eager to try the tip. “My dad can’t grow anything so I’ma make sure to pass this info on to him,” said one user. “Hopefully something will live.”

“Mulchos gracias,” joked another TikToker.

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