Coconut fiber is a renewable alternative to peat moss

By Lloyd Thompson
WSU Chelan/Douglas County Master Gardener

Lloyd Thompson
Lloyd Thompson – WSU Extension Chelan/Douglas County Master Gardener – Provided photo

I have used peat moss as my primary go-to potting soil base in most soil mixes for years, as well as a major soil amendment for improving the mineral soil matter in landscapes. It works amazingly well because it is lightweight, holds soil moisture extremely well and is readily available.

As climate change discussions “heated up” (no pun intended), I started thinking more about things I need to address. Peat moss is a specific type of peat, formed in areas with a high concentration of sphagnum moss. Peat moss is peat, but not all peat is peat moss.

One issue is that while peat moss is a naturally occurring product, it’s not sustainable to use at the current rate of consumption. It takes up to 1,000 years for peat moss bogs to form and mature and we are using it at a much faster rate than what it can be produced.

The other issue is once it’s harvested and used, it begins to release the carbon that was locked up in the cold, wet bogs as it breaks down over time. We are also changing a sensitive environment by removing the peat moss and its water-holding capacity from its natural ecosystem.

I must admit, the first time I saw coconut coir I was pretty sure it was a ridiculous idea. Why would I use it instead of sticking with peat moss? Coconut coir is a fiber that forms the husk around the inside portion of a coconut. With a pH around 6 it works well for most plants.

I am by nature usually open to change, and after using some coconut coir fiber-lined hanging baskets I started to appreciate how well plants did in them. The liners held lots of water, helping the soil temperature stay cooler. Of course, I was still using a peat moss-based soilless mix in the liners, so I had a ways to go before I got out of the peat moss habit.

The nice thing is coconut fiber can be ground similar to peat moss, chipped for use as a mulch or as a long fiber for basket liners. It holds moisture well and is more green-friendly since it’s a secondary food byproduct, and it lasts longer before breaking down than peat moss.

Coconut fiber can hold moisture, improve soil structure, help with aeration and drainage, and has become readily available in many garden centers. It was actually used extensively in the 19th century before peat moss was first widely used.

There are other alternatives to peat moss, such as compost, manure, wood chips, sawdust, leaf mold, pine needles and bark mulch. Most have a narrower band of use than coconut fiber and peat moss due to some restraints related to pH, fertilizer and moisture. That leaves coconut coir fiber a greener choice and a better alternative to using peat moss.