Mulch is a common addition to many gardens and landscapes. With the benefits it provides, it easy to see why! It helps control weeds, reduces soil evaporation, prevents soil erosion, and encourages microorganism activity in the soil. It’s reasonable to assume that you can’t go wrong with mulching—but that couldn’t be farther from the truth. Improper mulch application can be detrimental to a tree’s health!
Improper mulching (pictured right) is a kiss of death for your trees, and especially new plantings, where you see it very commonly. When you pile mulch too high around the trunk of the tree, the bacteria that live in the mulch mistakes the tree trunk for something they are supposed to decompose. On top of that, with the mulch piled high, mice and voles are able to tunnel to the tree trunk without being exposed to their natural predators. Once they get to the trunk they chew through to the inner bark, cutting off the tree’s flow of nutrients and essentially starving it. But that’s not all! Once they’ve chewed through some of the bark, it attracts insects that will feed on it as well, spreading diseases as they do. With all of that occurring, there isn’t a very bright future in place for the tree…In a few years, your investment will likely be dead.
Preventing this is simple! As you’ll see in Fig-1, only apply mulch about 2-3 inches deep, and always make sure the trunk flare is visible. The size of the mulch ring you apply should be approximately the same as the trees drip line- which is defined as the point on the ground where water will drop off the widest-reaching branch. That’s all there is to it!
Mulch boldly into the future with your new knowledge, and remember to beware the mulch volcano!