Peat moss and Coconut fiber comparison. http://www.durgan.org/URL/?BRTHJ 8 September 2009 Peat moss and Coconut fiber comparison. Using my home potting mix and planting seed, it was found that wetting of peat moss in the mixture is often incomplete. I attribute this to the dust-like structure of the peat moss. The water makes the small peat particles float and wetting throughout the pot was often marginal. For the last two year coconut fiber has been used in place of peat moss to eliminate the problem. Peat moss is environmentally unfriendly. Coconut fiber is a renewable resource. Coconut fiber has structure and absorbs water readily. I suspect when peat moss is mixed with potting soil that many of the dust like particles do not absorb water. Often the water simply makes the small seeds float to the top along with unwetted peat moss. This is most annoying when planting seeds in small pots. My opinion is that coconut fiber is superior to peat moss for most applications.