Compost (commercial compost) is a growing medium made of natural materials such as forest materials, bark, leaves, soil, and other components in our best attempts to recreate the natural balance of moisture, air and nutrients that most plants thrive in – an undisturbed forest floor. 

The composted forest floor naturally has layers and layers of leaves and other natural materials (wood, insects, even expired animals).  The top layer of leaves and other material that we see has just fallen recently.  The lowest layers of leaves and other material has degraded – rotted – into particles that provide nutrients to the trees that are producing the leaves.  And thus the cycle continues – forests feed themselves without help from mankind (and will do so long after we’re gone).