Comments by Wayne Handlos

1.Coconut and husk  2.Coconut fiber  3.Coconut peat 

4.Cocoa beans in pod   5.Cocoa bean hulls    6.Gorilla hair 

After announcing a new organic garden and hydroponic supply store in Arroyo Grande as a source

of coir as an addition to potting soil, the question was raised about the danger of coir to pets. This

article considers the ins-and-outs of pets and these exotic mulches.

Coir is material derived from coconut husks. Between the coconut and its outer shell, is a fibrous mass.

These fibers have been used for millennia as fiber for rope, doormats and brushes. The material between

the fibers is somewhat granular and can be used as a soil amendment. It is sometimes referred to as coco

peat. This is the material that is available at the organic garden store. It comes in 2 cubic feet bags or as

smaller bricks (which expand when soaked in water and after fluffing up it is added to soil).

Cocoa bean hulls are the outer shell of the cocoa beans which are used for making chocolate. After

cocoa beans are roasted the shell is removed and bagged for use as a mulch. People are attracted to the

dark brown color and the fragrance of chocolate of this material.

Gorilla hair (contrary to some beliefs is not removed from gorillas) is the fibrous bark of redwood trees

or western red cedar which has been mechanically shredded. The fibers tend to make an interlocking

mass of strands and are recommended as mulch for sloping areas in particular because it mats together

and does not slide down a slope. Gorilla hairs bears some resemblance to coco fibers and may account

for mistaken identity.

Now, what is the issue with dog owners? It has been reported that dogs will eat the mulch, become ill

and die. The problem seems to arise from the fact that the words "coco" (the nut from the palm tree) and

"cocoa" (the cacao bean) sound the same when pronounced. Then, are all these substances dangerous?

Cocoa bean hulls are dangerous to a degree because they may contain the compound theobromine

which is a stimulant found in chocolate (and cocoa bean hulls). This substance is toxic to dogs and cats

and is the reason we do not feed chocolate to ourpets. Dogs may be attracted to the chocolate scent

which cocoa bean hulls retain for a couple of weeksafter being placed in the garden. The odor soon dis-

sipates (to the human nose). If dogs ate the mulch they might be poisoned. Therefore, it is recommended

that cocoa bean hulls not be used as mulch. From personal experience, I would not use them because

when wet they become slimy and slippery and then are dangerous to walk on. It has been suggested that

cocoa bean hulls are treated to remove the theobromine, but with a boiling point of 290 to 295˚C and a

melting point of 357˚C this largely water-insoluble compound has not likely been removed.

Gorilla hair is so fibrous and tangled that a pet would have difficulty eating it. It is a problem with pets only

in so far as fibers might cling to the animal�s fur and be carried into the house.

It has been suggested that coir might be eaten by a pet and then swell up in the animal�s digestive tract and

cause problems. Again, it is unlikely that the fibrous coco fiber (which is used as liners in hanging baskets and

those bristly tan doormats) could be ingested in any quantity by a pet. The coco peat, which is recommended

as a soil amendment, looks, feels and smells like soil and when mixed with other components of potting soil

would not seem to be attractive to animals. Even if an animal ate the potting soil, the coir peat would already

be hydrated and would not swell up inside the pet. Because of the cost, coco peat would not normally be

used as a mulch in any case.

Among the products considered here, cocoa bean hulls would seem to be the only substance used as a mulch

that is potentially dangerous to dogs (and to a lesser extent of cats). Its use is not recommended.

2019, Central Coast Geranium Society (CCGS )