Purdue University Warns Against Over-Mulching Trees

There are several benefits to adding a tree or two to your yard. For starters, more trees in the world are never a bad thing considering their importance to the ecosystem. But they can also provide shade, and on a superficial level, can add curb appeal to your property. However, if you want that new tree to thrive and live for decades to come, there's one thing you should avoid during the planting process.

Too "Mulch" of a Good Thing

I recently saw a friend share a post from the Bee-Friendly Gardening group on Facebook claiming that piling mulch around the base of your trees can actually harm the tree, or even kill it completely over time, despite the fact it looks nice (you can see the post here). Since I don't take anything I see on social media, or the internet in general, at face value, I decided to do a little research to see if what the post claimed was true.

Get our free mobile app

True or False: Over-Mulching (a.k.a. "Volcano Mulching) Can Kill Trees

Pattanaphong Khuankaew

This is true. John E. Woodmansee with Purdue University Extention (who has the perfect last name for someone in the world of agriculture, in my opinion) wrote about planting trees ahead of Arbor Day earlier this year and specifically mentioned the danger "volcano mulching" can pose to trees.

The common mistake many homeowners (and even some commercial developments) make is mounding a “volcano” of mulch around the tree...no mulch should be in direct contact with the trunk.

Leaf & Limb on YouTube / Canva

Again, while piling mulch several inches up the tree's trunk may look pretty to the overall aesthetic you're going for in your yard, what it's actually doing is slowly killing your tree. John Bonkowski with Purdue University Landscape explained how in an April 2020 article.

...when too much mulch is applied (4-6 inches or more) and is in contact with the above ground trunk, you can effectively change the “perceived soil line” by the tree. This can trick some trees into developing roots directly out of the trunk that grow into the mulch which are more susceptible to drought stress than below ground roots. Thick mulch layers can also cause established roots to grow within the mulch layer above the soil and circle around in the tree. Roots that circle around the tree have the potential to grow into other roots (even the trunk flare) and girdle the vascular system of the tree, leading to stress and, under severe circumstances, early death.

So, how should you properly mulch your tree to help it grow and live a long, healthy life? Take a look at this video from Leaf & Limb on YouTube to find out.

[Sources: Purdue University Extension / Purdue University Landscape Report / Leaf & Limb on YouTube]

LOOK: Stunning vintage photos capture the beauty of America's national parks

Today these parks are located throughout the country in 25 states and the U.S. Virgin Islands. The land encompassing them was either purchased or donated, though much of it had been inhabited by native people for thousands of years before the founding of the United States. These areas are protected and revered as educational resources about the natural world, and as spaces for exploration.

Keep scrolling for 50 vintage photos that show the beauty of America's national parks.

RANKED: Here are the most popular national parks

To determine the most popular national parks in the United States, Stacker compiled data from the National Park Service on the number of recreational visits each site had in 2020. Keep reading to discover the 50 most popular national parks in the United States, in reverse order from #50 to #1. And be sure to check with individuals parks before you visit to find out about ongoing, pandemic-related safety precautions at www.nps.gov/coronavirus.