MULCH

A weapon for use with rhizosphere wars.

First allow me to define a few terms:

Fertilizers are Soluble salts of essential elements.
Food is energy plus elements essential for life.
Forest - A forest is a highly ordered arrangement of living organisms living in, on and around (dead, dying & living) trees in such an highly ordered fashion it assures high quality survival for all.
Soil is a substance made up of sands, silts, clays, decaying organic matter, air, water and an enormous number of living organisms.
Synergistic - Infections that result in benefits to both parties are called mutualistic.  When the benefits are greater than the sum of the parts, the association is called synergistic.
Synergy means that the efficiency of any system will be increased as we add associates. 2+2=10
System - A system is a highly ordered connection of parts and processes that have a predetermined end point - product, service.
Vitality is the ability to grow under the present conditions; dynamic action.  We can increase or decrease vitality.
 
 
 

Boston Market - West Chester Pennsylvania

Mulch can be a very attractive asset to a landscape as well as a health treatment for the system if done correctly.  First I define mulch as anything that will facilitate the mycorrhizae.  Mulch comes in different gradations.  As fine as composted leaves and as large as a nurse log of a redwood in a natural forest. A good mulch program will include as many gradations as possible where and when possible.  Mulch can provide essential elements, water during dry times and carbon for our sick soils.
 

Mulch can also speed up the breakdown of nasty chemicals used on lawns as well as reduce soil compaction while facilitating beneficial microorganisms.


 

In any natural undisturbed forest we have visited, where things go right for trees, we have witnessed all gradations regularly. Here they have formed an A shape. Deer are not a problem here.  Some areas, due to natural disturbances such as tornados, had more nurse logs than others.  In this case the soil was getting a good sock of carbon.
 
 

Composted Leaves
Composted leaves can improve soil health as a top dressing to lawns and tree areas.  For trees,  leaves would be best if mixed with composted tree trimmings. In the Northeastern United States early spring and the fall would be the preferred time for top dressing lawns with composted leaves.  Backyard composting is becoming more and more popular.  Some Counties in Pennsylvania,  such as Chester,  along with The Pennsylvania Resource Council are offering composting courses with certification for residents.
 

Please note that composted leaves are an excellent soil additive for organic gardening. This one happens to be in Wallingford Pennsylvania.
 
 
 
 
 
 
 
 
 

Composted Tree Trimmings
The most commonly used gradation is the size of tree trimmings (chips) that have composted for one year or more.  It should be mentioned that fresh chips should be avoided.  They will attract undesirables. Composted material, such as this, will stimulate bacteria within the soil and make certain essential elements available.  This gradation is not as efficient for reserving water,  for dry times, as eco-art nurse logs.  However this gradation is just as important.  This type of mulch should be 3-4" thick and flat.  Mulch should not contact stem tissues including the flare of the trunk.  The mulch is best if at least 6" from the base of the tree where is has little use.  The distance the mulch should be placed from the tree will vary under circumstances but 3 to 4 feet could provide a great benefit for the system.  Mulch made up of all bark should be avoided for it is made up of primarily suberin and will not add food (carbon) for the soil.  Some tree care companies have begun to separate chips by species, thus providing high quality custom blended mulch, at an additional cost.  We began several years ago bringing composted conifer trimmings back for trees such as spruce, hemlock and pine, i.e., where and when possible.

Eco-Art Nurse Logs
Eco-art nurse logs - Those who live in the Philadelphia area know what I am talking about: it is a most recent art form which enhances the beauty of the landscape, while at the same time increasing the vitality of the living soil, the trees, and the associated organisms. In general, nurse logs return to the soil some of the elements taken from it during growth and, as a source of food, enhance enzymes e.g. those which turn cellulose into sugar. They also serve as water reservoirs as well as shelters for beneficial fungi. When we have many organisms connected we call that a eco-system. Eco-art nurse logs are logs from urban tree removals that are at least 2 feet in diameter by at least 4 feet long. In nature, at times, they are water reservoirs for trees during dry times, seed beds, reduce soil erosion, add elements such as calcium when trees need it, benefit wildlife and much much more.
 
 
 

Not every urban situation is right for this gradation of mulch, however where it can be used it benefits the system.  As certain professionals move forward and begin to plant trees in groups rather than as single soldiers or lions in a zoo, the home for these natural ecological stages of trees will increase.  Trees have many ecological stages.  We are finding that the bigger the nurse log the better the chances of maintenance free plants within.  In wood lot management and tree farms,  it would be nice to leave as many as possible perpendicular to the slope to collect things.
 

I have dissected many nurse logs and have found many living organisms including colonies of certain bees.  This log was 2' in diameter and the arrow points to the bees cavity.  This is an important issue due to the fact we are at an all time high pollination crisis.  The length of decomposition of these nurse logs will depend on the species of tree.  In natural forest, undisturbed, American Chestnut logs would remain for more than 50 years if not removed by man.
 
 

Things that should be avoided
Herbicides really have little if any benefit for the tree system, soil, wildlife or applicator.  Black
plastic will separate living soil from food (carbon) so I suggest avoiding that where tree health is
an issue.  I also do not see much value to weed mats for soil management.  One does not have to
look very far to find people willing to work for a few hours pulling weeds.

When mulching trees with grass beneath them, removing the grass can do more damage in many cases.  The roots of grass grow deeper than many non-woody roots of trees.  We suggest
mowing the grass as low as possible and placing the mulch on top of the grass.  Grass may be
pulled by hand at the trunk flare of the tree.  I hope in the future we will be able to identify more plants that grow with trees with the interest we now have with pests. Many of these plants have unique benefits that go unnoticed too often and are considered weeds. Some of the benefits can be very synergistic.

Things to be aware of.  When plants grow through the mulch - its fine, trees seldom grow alone in nature and some plants have many symbiotic effects.  It would be nice to try to identify the plants that grow and see if they may be common in undisturbed areas to be with the tree or shrub.  Also proper mulch techniques could serve as good soil management for fruit trees as well, for they also require healthy soil.

Things to educate client about.
To start with, the benefits of ants and bees.  Too often clients will see ants or bees and break out
the arsenal of pesticides to slaughter.  Ants can be very beneficial for trees, and will not create
an ant problem within your house.  If they have carpenter ants their house has rotten wood.

Explain that the area with composted tree trimmings applied is not such a good place for a spring garden.  This causes in many cases flowers disease.  However a professional chain saw operator could cut a tray in the nurse log for planting and then you would have eco-art.

Fertilizers are salts of essential elements. As far as fertilizing goes, in nature manure is a very common fertilizer.  The addition of composted manure in small amounts to the tray of the eco-art nurse log may benefit the flowers and trees.

Trees are like big batteries.  They store energy in many forms.  Mulching with all gradations is one way of getting the energy to the soil where it is much needed.
 
 
 

Some suggested readings:

Natural History; 78: 42-47 1969 Shigo, A. L. Death And Decay of Trees

Phytopathology: Vol.69, No. 10, 1979 Shortle, Walter, C.
Mechanisms of Compartmentalization of Decay in Living Trees.

Tree Care Industry (TCI); Vol IX, Number2 - Feb. 1998; pg 40;  Keslick, John
Art in Arboriculture

National Wildlife Dec /Januray 1998 pg 14-15 Woodier, Oliwen
Turning Deadwood into Lively Homes for Wildlife

National Wildlife Feb / March 1998 pg 30-35 Stewart, Doug
Prosimians

Bioscience Vol.  41 No.  9 (October1991) Harmon, M.E.; Hua, C
Coarse Woody Debris Dynamics in Two Old-Growth Ecosystems

USDA Research Paper INT-RP-477, Sept 1994 13 pages Graham; Harvey; Jurgensen; Jain; Tonn; Page-Dumroese
Managing Coarse Woody Debris in Forest of the Rocky Mountains

1991 Page-Dumroese; Harvey; Jurgensen; Graham
Organic Matter Function In The Western-Montane Forest Soil System

Science Vol. 247, Feb 1990; pg 699-700 Harmon, M.; Ferrell, W. K.; Franklin, J. F.
Effects of Carbon Storage of Conversion of Old-Growth Forest to Young Forest

Tree Care Industry Volume VII, Number 11-November 1996 - Shigo, A.L. A Touch of Chemistry

Tree Care Industry Volume VII, Number 10 -October 1996 Shigo, A.L. Troubles in the Rhizosphere

Shigo and Trees, Associates Second Edition - Hardcover, 619 pages, 688 A NEW TREE BIOLOGY

Shigo and Trees, Associates Hardcover, 440 pages, 600 references, index.  MODERN ARBORICULTURE

Shigo and Trees, Associates 80 Pages 100 TREE MYTHS

Daniel B. Wheeler Mycorrhizae, Voles, Owls, Trees and Man

Daniel B. Wheeler Nurse Logs, Voles, and Hemlock Regeneration

Text & Graphics Copyright © 1999 Keslick & Son Modern Arboriculture