Homeowners and home gardeners find wood mulches very useful in the garden, the flowerbed, and around the yard for controlling weeds. However, mulch presents its own set of problems. This article looks at the most common problems that arise from mulch and how to avoid them.
Sour mulch is one of the worst problems one can encounter. It is when mulch is not getting sufficient oxygen to decay normally, when there is insufficient oxygen, the mulch will not decay ordinarily but through anaerobic activity, which causes acid that results from the anaerobic decomposition, which builds up quickly to levels that are toxic to the plants. The acid gives off a sour smell similar to vinegar or alcohol, and this alerts the presence of sour mulch. Always smell the mulch before buying it. Before spreading sour mulch, it must be spread out thin and saturated with water, then allowed to dry and air out for a few days, after which it will be safe to spread. If the mulch is already spread, and goes sour, it has to be pulled off and treated. Mulch seldom goes sour if spread no thicker than one to three inches deep.
Artillery fungus is another serious problem for mulch, it does not harm the plants or mulch as much as the property. The fruiting structures of the artillery fungus shoots its spores into the air, the spore mass sticks indiscriminately to plants, the house, cars, sheds, and anything else it lands on, and is extremely difficult to remove. Wet conditions encourage this mold, and it grows in wood-based mulches, especially cheap mulches.
Contamination is another problem in mulch. Some companies and municipalities recycle wood into mulch, but the mulch is not always made of the best wood. The wood sometimes decays faster than good mulch and can contain chemicals that are not fit, especially if the mulch is used in a playing area or an herb or vegetable garden.
Nitrogen depletion of the soil is a problem with all wood based mulches, the nitrogen is drawn from the soil to use in decomposing. To remedy this, a nitrogen based fertilizer or soil amendment can be used prior to applying the mulch.
Those are the major problems associated with wood mulch. A slime mold is also common, it comes in bright orange or yellow and the slimy mold can grow over a foot. They do not do any harm and can be left or removed if their appearance is found to be undesirable.
These are the liabilities of using mulch. Through the selection of mulch types, preventative action, and through knowing what to be alert for, you can avert most of the problems associated with mulch.