So you know it's good to mulch a tree, but do you really know why, or the proper way to do it? Listed below are the reasons for all that hard work and a diagram of how to properly do the job. You can also visit the Morton Aboretum's website at http://www.mortonarb.org/news/why-and-how-spread-mulch for additional information.
Mulching reduces the loss of soil moisture.
The soil structure is improved, making it more like a natural forest soil.
Soil compaction and erosion are reduced.
It reduces the impact of water droplets hitting the soil surface, thereby, reducing soil crusting. This reduction in crusting increases water penetration into the soil.
Competition for water and nutrients from surrounding turf is reduced.
The root zone beneath the mulch is kept warmer in winter, cooler in summer, thus reducing root damage.
It provides a barrier for the tree against lawnmowers and weed whips.
Top growth and root development are increased.
The appearance of newly planted trees is improved.
The pH of the soil is lowered, aiding the root’s ability to take up nutrients.
Long term nutrient availability is increased.
Never pile mulch or soil against the trunk of the tree. This promotes decay and the development of trunk encircling roots, shortening the life of the tree.