Landscape mulch is a layer of some type of matter that is spread over the top of the ground. It can be made up of a number of different materials but the intent is to achieve one or more of the following impacts:

  1. Conserve Moisture - Mulch will shield the soil from the direct rays of the sun thus reducing the amount of evaporation considerably. This will help to reduce the number irrigations and the amount of water that needs to be applied.

  2. Weed Control - A layer of mulch will force seedlings to push their through extra layers to reach the sunlight. Many weed seedlings will run out of energy and not be able to make it to the sun. Certain perennials weeds will also be limited by mulch but may still make their way through to the top.

  3. Aesthetics - In beds and borders, a primary role of mulches is to provide a uniform and pleasing background for the plants. Ornamental mulches when used throughout the landscape will provide a unifying effect to the garden.

  4. Cool the Soil - By shading the soil, it will keep the root environment of nearby plants cooler than if they were exposed to full sunlight. For certain plants such as clematis vines, this is a very valuable impact.

  5. Warm the Soil - Although not commonly considered in the ornamental landscape, certain mulches, especially plastics can allow soils to warm up sooner in the spring and hold heat throughout the season. This is more often used in the vegetable garden and not in ornamental beds and borders.

Types of Mulching Materials
  • Organic Mulches - Probably the most common type of ornamental mulch for the home landscape are those of an organic nature. This would include shredded barks, wood chips, coccoa bean hulls and others. Generally a 2 or 3 inch layer is applied evenly over the beds and borders each year.

  • Inorganic Mulches - These materials do not decompose and consist of rocks, gravel, brick chips and others. Generally, some type of landscape cloth or plastic is placed under this type of mulch. The rocks may not decompose but the underlayment usually does over time causing future messes.
  • Artificial Films - Traditionally, black or clear plastic sheets have been used as mulching materials in landscape beds. These products do not allow for the penetration of water and can cause problems over time. Also, they tend to break down with exposure to ultraviolet lights, become brittle and break apart. There are now landscape mats which will allow for water penetration.

Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.


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