How To Mulch A Tree Or Shrub

Mulching seems natural.  After all, mulch helps re-create a forest environment, where decaying leaves, twigs and branches blanket the ground.  As they break down, they slowly feed plants and they help the soil stay moist.  Plus, the natural carpet looks nice.

What is unnatural is the current practice of making gopher mounds of mulch around the base of plants.  Not sure what I mean?  Drive around your neighborhood and look, especially at newly landscaped areas.  There they stand - poor, helpless trees and shrubs being swallowed by wood-chip piles the size of the Great Pyramid (well, almost).  Not only do those mounds look unnatural, but they also hurt plants by depriving roots of air and water.  

Below are the basic steps to mulching the right way.  Use whatever mulch works for you - bark, compost or shredded leaves, for example.  But no matter what you choose, make sure that it is fully composted.  

Uncomposted mulch will tie up soil nitrogen as it decomposes, starving your plants and it may steam, or 

create heat and acid that will burn tender new plant roots.

•  KEEP MULCH SEVERAL INCHES AWAY from the trunk.  Mulch helps to hold moisture; that’s a good thing  except when mulch is piled against a plant base.  Stems, unlike tree roots, are not adapted to being moist all the time.  By putting mulch too close to the stem or trunk you risk problems with moisture-loving insects, fungi and rodents.

•  APPLY MULCH so that when it settles, the layer is no more than 2 to 3 inches deep.  If mulch is applied too deeply (or has a fine texture like sawdust), air and water may have a hard time penetrating the mulch layer.  Deep mulch is especially problematic for plants with fine root systems, such as Azaleas, Rhododendrons and Japanese Maples.

•  SPREAD MULCH all over the ground directly below the canopy.  (This area is known as the drip line).  Doing so keeps weeds and grass from competing with roots.  It also prevents injury to the stems due to close shaves with the lawn mower or string trimmer.  Finally, it allows more of the root system to benefit from the moisture-conserving advantages of mulch.

Information courtesy of Organic Gardening