The shell of the coconut (Cocos nucifera) are surrounded by a husk called coir that is processed commercially for its long, twisted fibers used to make doormats, ropes, carpets and for upholstery stuffing and other purposes. The granular dust between these fibers, called pith or bast, is compressed into cakes or bundles called coco peat or coir peat. Coco peat has qualities that make it useful as a soil amendment, potting mixes and for hydroponic growing systems.
Coir fibers are removed by soaking the coconut husk. When the fibers are washed, the pith is put through a sieve to remove long strands of fiber, grit, sand and other residue. It is then washed to remove salts and dried before it is pressed into briquettes or blocks of coco peat.
Coconut fiber pith contains millions of sponge-like capillaries in a granular structure that enables it to hold eight times its weight in water for extended periods. When it is compressed into coco peat and added to soil, coconut fiber pith helps provide air to the soil and gives space for plant roots to develop. It is free of weed seeds and disease, and its natural pH rating ranges from 5.7 to 6.5, enabling it store and release soil nutrients in almost any soil. The Indian Council for Agricultural Research says its high content of lignin means takes up to 10 years to decompose. Lignin fills the space between the walls of wood cells and constitutes from one-quarter to one-third of the dry mass of wood.
Adding water to blocks of coco peat, results in a fluffy, organic potting medium. Used as a soil amendment, it helps aerate soil and make it hold more water and nutrients. It is added potting mixes as an alternative to sphagnum moss or peat. Blocks of coco peat are used as a growing medium in hydroponic growing systems. English horticulturalists first used coconut pith as a growing medium in the late 19th century. Pith is also used as a fertilizer.
Coconut fiber pith is a byproduct of harvesting coconuts, as such it is a renewable resource. Those touting its use in coco peat say coco fiber pith is an excellent replacement for sphagnum peat moss that is obtained by stripping the tops of bogs in northern Europe, northern U.S. states and Canada.
Because of its capacity to absorb, coconut fiber pith is used to soak up hazardous liquids including ink, paint, coolants, gasoline, diesel, oil and solvents.