Cedar is one of the most commonly used varieties of mulch. The basic purpose of mulch is to help the soil retain moisture, especially during hot temperatures. Cedar mulch is able to accomplish this, while simultaneously benefiting plants in numerous other ways.
Cedar mulch produces a strong fragrance which is pleasant for humans. However, insects and other pests are repelled by the scent. This makes plants mulched with cedar less likely to become infested with pests such as aphids and earwigs. Heavy applications further reduce the number of insects and increase the pleasing fragrance.
Because of its light color, cedar mulch is also one of the best choices for maintaining a constant soil temperature. Bark mulches are usually dark, and will absorb sunlight and increase the temperature of the soil during hot weather. The light red of shredded cedar reflects sunlight during the spring and summer, and will also help prevent the ground from thawing during late winter. Constant thawing and freezing cycles can be damaging to plants, but using cedar-based mulch will significantly reduce the trauma of changing seasons.
Shredded mulch is the most common form of cedar mulch available, and will stay in place better than other varieties. As the mulch becomes weathered, instead of sliding away, it will mesh into itself, eventually forming a secure mat. This mat will hold together during severe weather, and is less likely to break up than larger bark chip mulches.
The mat formed will also prevent sunlight from reaching the soil around the plant, eliminating the possibility of weeds. Chip mulches can allow both light and germinated weed seeds to filter down to the soil, and eventually sprout. All previously established weeds under the mulch will be suffocated as well, and will be unable to grow or receive sunlight.
Cedar also decomposes at a faster rate than other types of mulch. This increases the amount of nutrients that are released into the soil, making it more fertile. While it will have to be replaced more often, diseases are less likely to form with fresh mulch being applied more frequently.
Safety is another advantage of cedar mulch. Almost all shredded cedar mulch is untreated by chemicals. As it decays, poisons won't leach into surrounding soil and plants. This is especially helpful when used in organic vegetable gardens or around fruit trees. This mulch can be used under and around playground equipment and other areas where children frequent. The mulch is soft, and will not cause scrapes or splinters when it comes in contact with the skin.