Forest soils contain a biodiversity of living organisms which the trees
need.  All of the natural, organic nutrients required for a trees health and growth can be found in the layer of composting mulch on the forest floor.  This mulch layer is replenished annually by leaf drop and branch/tree failure and decomposition.  The soil in a forest stays cool and retains moisture due to the canopy cover and mulch layer.  Tree roots can grow freely with few obstructions.

Urban soils have poor biodiversity with minimal living organisms and organic material.  Most often the soil is compacted or contains foreign material due to construction.  The trees natural nutrients (decomposing leaves) are raked up annually.  Soils in the urban environment can become hot and dry due to the lack of tree canopy and mulch layer.  Tree roots compete with lawns, gardens, patios, pools, foundations etc.  The use of chemical fertilizers is often used to encourage lawn and tree health, this practice leads to rapid but not long lived improvement.

Composted mulch is like giving your trees A handful of the forest floornew pics 006

This mulch is comprised of wood chips and leaves which have been composted over time.  The natural organic nutrients are readily available to the tree roots.

Composted mulch contains beneficial micro-organisms and worms which help condition the soil.  Over time as these benefits are replenished in the soil the tree health improves which reduces maintenance costs.  Mulch helps keep the soil cool and moist and is aesthetically pleasing to the eye.

Bark Mulch which is commonly found in most nurseries and garden centers is not composted and therefore does not have nutrients immediately available for the tree roots.  This mulch will begin to compost on the site which can draw nitrogen from the soil away from the roots.  Although this type of mulch will also keep the soil cool and moist and can be pleasing to the eye it contains no beneficial micro-organisms to help condition the soil.