All About Mulch

Proper application of mulch helps control weeds, (which also saves you a lot of time), maintains a more even soil temperature, prevents dirt from splashing on your plants, gives your garden a neat appearance, and in some cases, can improve your soil and inhibit some plant diseases.  Used around trees mulch can even reduce damage from weed whackers.

There are two basic types of mulch, organic and inorganic.  Which type you choose depends on what you are trying to acomplish.

Examples of organic mulches are wood chips (often dyed to create a variety of colors), pine needles, grass clippings, bark, leaves, hay, compost and many other materials that usually orginate from plants.  Soil quality is improved through better aeration and added nutrients as these decompose and earthworm activity increases. The rate of decomposition varies by material.

Inorganic mulch can include stone, gravel, black plastic, landscape fabric and rubber mulch made from recycled tires.  If you're looking for a long lasting mulch solution, this is your answer.  However, since these do not decompose, they won't improve your soil.

Ground cover plants can be used as a "living" mulch.  They are usually low, fast-growing plants that provide weed control and moisture retention.  Be sure not to plant anything too aggressive that will take over the other plants in your garden.

Some of the more unusual mulches include oyster shells, aluminum foil, chicken grit, ground cork and asphalt.  To see a list of various mulches, showing the advantages and disadvantages of each, visit mulch materials.

Just as important as the type of mulch you use is correct application.  Since mulch can affect the temperature of the soil, it should be applied at the proper time of year.  In early spring it will allow the soil to warm slowly.   In colder climates, this helps prevent the freeze/thaw cycles that can heave plants out of the ground.  Applied in fall, it will help keep the soil warmer later in the season.

Improper mulching can lead to problems.  If mulch is applied too deep, it can hold in excessive moisture and prevent air flow.  Slugs and snails love this moist environment. Very fine mulch can actually encourage weed growth (think potting soil texture).  Mulch should be kept from touching plant stems and tree trunks to reduce disease and insect problems.  Rodents will take up residence in a heavy mulch.  "Mulch volcanoes" is a new term used to describe mulch that's piled up too high against the base of tree.  Trees will benefit from a 2 to 4 inch layer or organic mulch, but more than that should be avoided. 

Your annual rainfall should be considered too.  Mulch prevents sunlight from reaching the soil which reduces evaporation.  If rain is scarce, mulch can absorb the small amount of moisture received and prevent it from reaching the ground.  Some mulches, such as leaves, can mat down preventing water from soaking through them.  Heavy rain can drench mulch and the ground, creating too much moisture and causing plants to rot.

So how much mulch is a good amount?  Generally 2 inches - 4 inches deep works well for most applications.  For an easy way to determine how much you need to purchase, use this convenient mulch calculator.

You can purchase mulch by the bag, which generally comes in 2 cubit foot or 4 cubit foot bags.  Most garden centers offer delivery with their truck, but it will likely be dumped in one spot and you have to haul it by hand.  You can usually bring your own truck or trailer to pick it up and they'll load any amount you need.  You can then back your vehicle right up to where you need it at home to eliminate the distance you'll have to move it by hand.

Applying mulch is a lot of work, but you'll reap the benefits later by less time spent weeding and watering.  If you use organic mulch you'll also be improving  your soil at the same time.  All of this will result in happier plants and more time for you to enjoy them!