Even though many people mulch for the perceived beauty of it, it’s important to remember that the biggest effect is under the mulch.

In addition to dirt and tree roots scientific evidence is demonstrating that in healthy soil there are wonderfully helpful — even necessary — fungi called mycorrhiza found in the top 2-3 inches of leaf litter and top soil. These mycorrhiza form an intricate network and are capable of bringing minerals and other nutrients from great distances to benefit the tree. In exchange the tree gives them some of its sugars.

Along with the sugars these mycorrhiza need decaying mater for food. They seem to prefer leaves and rotting sticks — the very thing nature would have provided if we hadn’t raked it away. The healthiest trees I find are in the woods undisturbed by urban life. Their home has never been raked or mulched with double ground wood bark which in many cases blocks water and is no source of nutrients for the mychorrhiza which then   die. (The mychorrhiza are a good reason not to spray fungicides.)

At Boxerwood we follow the suggested "Forest Floor Mulch" designed to bring the needed diversity to the mulch layer. 1.) Spread a little compost 2.) Spread leaf mulch and 3.) place a thin layer of wood chips to hold the leaf mulch in place.
 
Mycorrhiza do amazing things. I can examine a tree that has been bought, planted properly and mulched with double ground wood bark. In a short period of time the ground under the mulch feels either dry and compacted or overly wet and compacted. I can examine another tree that has been planted, inoculated with mycorrhiza and given Forest Floor Mulching and I find worms, moisture and almost loamy soil. It is friable. You can almost dig  with you hands.

If you suspect your plants are struggling along without mycorrhiza, there are two ways to get it. You can buy it. They have them for trees and shrubs and for flowers, etc. Or you can go and get a small handful of dirt from under a healthy vigorous tree of the same variety.

After you spread it be sure to provide the proper mulch....for the tree, the soil and the Mycorrhiza.