What should be one of the most simple tasks in gardening is often one of the most egregiously performed. There are many benefits to mulching; namely it helps retain moisture in the soil, prevents the number of weeds that come up and it helps give a clean, crisp and finished look to your planting beds. It takes very little skill yet it is one of the most often improperly performed tasks by both home gardeners and professionals alike. With all of the aforementioned benefits of mulch when it is not applied correctly it is extremely detrimental to all plant material but mainly woody shrubs and trees.
When too much mulch is applied you are creating what is referred to as a mulch volcano. This creates a wonderful warm and moist environment for insects and fungal problems but the biggest issue it causes is growth of new roots above the root flair. When these new roots start to grow inside of the mulch volcano they hit the perimeter of the mulch and begin to circle the tree. This continues to wrap itself around the tree until it literally chokes the tree to death! There must be companies that are making a living off of selling mulch because some of the examples are extreme (see the pictures). The irony of all of this is that it takes more time to complete the task because you are applying more mulch and it takes longer. Take notice as you drive around town how many people and companies are not doing this correctly. Great intentions in planting are being killed off by over zealous and improperly trained mulchers. You are now forewarned; don’t kill your trees slowly!