Coir or coconut coir is the fibrous material found between the hard internal shell and outer coat of a coconut. As a growing mix or soil amendment, it improves air porosity, even when wet, and aids in moisture retention. Coir absorbs 30 percent more water than peat and is much easier to re-wet, when dry. We use it in some of our terrestrial orchid mixes, most often in 1:4 or 1:6 ratio of coir to perlite. It’s more expensive than peat, but we anticipate the price will trend downward as it becomes more readily available on wholesale markets.