Natural, or organic, mulches are an excellent way to retain soil moisture, add organic material to the soil, and reduce the amount of weeds in the garden. Natural mulches include pine needles, straw, grass clippings, wood chips, and shredded bark. Another mulch becoming common to find is cocoa shells.
Cocoa shell mulch is an attractive, dark mulch that will not bleach in the sun and is fairly easy to use because is lightweight. It is a natural by-product of the chocolate industry, so it is also environmentally-friendly and, for the first few weeks, has a pleasant chocolate aroma.
Unfortunately, this mulch is not for everyone. Pet owners - especially dog owners - should steer clear of this mulch. The cocoa shells, just like chocolate, contain the chemical theobromine. This naturally occurring compound - found in many plants, including cocoa beans - can be harmful to dogs. And, the mulch has an odor that many dogs find attractive to eat.
A few years ago, the American Society for the Prevention of Cruelty to Animals investigated several cases in which dogs ingested cocoa mulch. The organization studied those cases in response to the growing number of reports about dogs eating that type of mulch.
The ASPCA's study revealed:
• Vomiting was reported in 50 percent of the cases
• Tremors were reported in 33 percent of the cases. In these cases, the amount of cocoa mulch ingested by the dogs was described as "large or significant"
• Tachycardia (rapid heart rate), hyperactivity, or diarrhea were reported in 17 percent of the cases
• High amounts of cocoa mulch can cause tachycardia, muscle tremors, seizures, and even death. One dog died after eating a large amount of cocoa bean shell mulch that contained 0.46 percent theobromine
• There were no clinical signs of illness in 33 percent of the cases