Mulch is an essential component of landscaping.  Far from being merely aesthetic, organic mulch enriches soil, protects plants and suppresses weeds.  There are many varieties and colors of bark mulch available, but other organic materials like grass clippings, leaves and pine straw can also be used.  The type of organic mulch you choose is an aesthetic choice.  The effectiveness of mulch is determined by how and where it is applied.

A layer of mulch should be 2-4 inches thick.  When adding fresh mulch to a bed, break up any chunks or compacted spots of old mulch.  Then add the layer of fresh mulch being careful not to exceed 5 inches in total depth. For a clean landscape bed edge, shovel the edges of the beds so that the mulch layer is even with the grass height.  This will prevent the mulch from washing into the lawn and give a sharply defined bed line without using plastic bed edging.

As organic mulch decomposes, plant enriching nutrients are deposited into the soil.  Certain organic mulches can be selected for the type of nutrients they deposit.  For example, pine straw can be used to raise acidity levels in a plant bed.  A mulch layer will also help to retain water and insulate plant root systems from extreme temperatures.  Mulch helps top soil from becoming compacted or eroded away.

In addition to soil enrichment and protection, mulch protects plants from damage by lawn mowers and weed whackers that get too close.  Mulch will help to suppress weeds, but never lay mulch over top of landscape fabric or plastic sheeting.  As mulch decomposes, a layer of soil/compost will form on top of the sheeting giving weeds a place to germinate.

Regardless of the type or color of organic mulch, plants and trees will flourish surrounded by a layer of properly laid organic mulch.


Sheena Wilson has  a Landscape & Nursery Management degree from Michigan State University and 10 years experience in the landscape and gardening business.  If you have specific questions you want Sheena to answer, you can leave a message below or send an e-mail to and put “Ask Sheena” in the subject line.