Beware the Mulch Volcanos! They Are Just Not Good For Your Trees.
It's that time of year where the mulch comes out to pad the areas of lawns that nobody wants to mow or add to the landscaping for an ornamental touch.
Mulch is basically a mixture of organic materials, like sticks, wood shavings, leaves, etc. The purpose of mulching is to help keep moisture beneath the mulch, to prevent weeds from growing where the mulch is laid and to also add some visual appeal.
One common place people will put mulch is at the base of trees, where the grass meets the trunk. There are some good practices to doing this so that trees won't rot at their base and/or grow roots into the mulch. One common mulching technique that you may come across that is not a good practice technique is coined 'mulch volcanos'.
'Mulch volcanos' is a term used when mulch is piled high around the base of a tree and is actually not good for the tree.
Mulch is actually not something that arborists, and other educated professionals, are too fond of. It is agreed that proper mulching has it's benefits, including adding nutrients to the soil around trees, protecting roots during winter months and keeping moisture near the root system.
But, too much mulch, as in the case of 'volcano mulch' and you have too much opportunity for trees to be harmed, such as rotting the bark, rotting the root system, tempts improper roots to grow that will not help the tree, and, when conditions get dry, mulch can actually repel water- making trees not get sufficient water absorption.
Best practices from Penn State say to have your mulch be 3 - 6 inches deep, dispersed as to not physically touch the tree and extended out to the 'dripline' of the tree.
For more information on 'mulch volcanos', check out this article from Penn State called 'Mulch Volcanoes Are Erupting Everywhere!'