Black Mulch Dangers
- Black mulch provides health to plants while providing a garden or flower bed with a non-traditional appearance---and is designed to allow the bright colors of plants and flowers to become more noticeable against a dark background. Plants that would otherwise fade into the scenery will stick out when black mulch is used. However, this type of mulch can create problems.
- Black mulch is made up of wood chips or strips. In some cases, mulch is made from CCA pressurized wood---which can cause serious harm to plants and the ground. Mulch that has been formed from raw wood is much better for plants and the environment. The wood pieces are then dyed using iron oxide or vegetable dyes. Some companies may use dyes that are not safe for plants, so it is important to check all labels.
- One of the biggest problems that black mulch produces is that sometimes the dyes or chemicals in the wood leech into the ground surrounding the plants and flower beds. According to several studies conducted by Solo-Gabirele and Townsend, Tolaymat and Blassino, in 1999, 2000 and 2002 respectively, recycled mulches were often made from CCA treated wood which stands for Chromated Copper Arsenate. This kind of wood contains arsenic. When the mulch is spread, the CCA leeches into the ground.
- The chemicals in CCA-treated woods are very harmful to the environment. However, that is not the only danger. The dyes in the mulch are chemically based. The chemicals in the dyes can cause damage to plants and the earth itself. Extreme weather such as rainstorms and extreme heat can cause the dyes to react and release chemicals into the ground.
- Another problem with black mulch is the issue of staining. Some dyes will come off during rain or snow, which will cause the dye to move from the mulch and into the ground. The mulch will appear ugly and dried out. Another problem that black mulch has is the issue of fading. During constant sun exposure, the black mulch will gradually fade to an ugly gray.
