Coconut coir, a bi-product of the coconut processing industry, is the fiber between the husk and the fruit of a coconut. A large number of products are made from the fiber including those well known to gardeners for lining wire baskets, planters and window boxes.
One of the uses for coconut coir fiber well known to gardeners, hanging basket liners.
Bio-degradable pots made from coconut coir fiber, similar to sphagnum peat, help in reducing transplanting shock. The lighter colored pot in the middle is actually a party crashing peat pot.
Coconut coir offers another benefit, it is an acceptable substitute for sphagnum peat as a soil amendment and potting mix component, with the added benefit of being a renewable organic resource that last longer than sphagnum peat before breaking down.
It is used to add bulk and aeration to potting mixes, can hold up to 9 times its weight in water. Because of its bulk and texture, once saturated the excess water is able to drain freely from the potting mixture.
Out in the garden coir is excellent as a soil amendment for lighter soils giving bulk and substance as well as helping with water retention. It has little effect on soil pH with a natural level of around 5.5-6.5. However Coconut coir, like sphagnum peat, is not recommended for heavy clay soils because it stays waterlogged in winter, then in summer, if allowed to get dry, becomes very hard to re-hydrate.
Coir marketed for gardeners comes in several different sizes and although seldom mentioned by retailers there are also two different grades, fine pith and coarse pith, both grades are acceptable for potting mixes.
You can see there are a lot of the longer fibers in this sample of coarse pith coconut coir, it is good for potting on mixes and as a soil amendment out in the garden.
The fiber strands are much shorter in this sample of fine pith coconut coir, it’s best use is in potting mixes for seed germination.
Coconut coir is compressed into blocks for shipping purposes, this greatly reduces the space it takes up, as you will soon realize when its time to re-hydrate any bricks you purchase.
This 1.4 Quart block will expand into 10 quarts of potting mix.
The process of making coconut coir ready for use is pretty simple. Add the required amount of water and wait a few minutes, it will absorb the water and expand to the finished product.
Follow this link for a how-to slideshow of re-hydrating compressed bricks and continuing on to make potting soil with coconut coir
There was a time when the coconut coir fiber process involved being rinsing using sea water and as a result much of the coir on the market had high salt content. This has changed in recent years and today is not usually a problem. Buying from a trusted source is your best safe guard for quality coir however if there is any doubt whether the product you have has been treated to remove the salt it is a simple process to do so yourself.
When re-hydrating your compressed coir brick, add extra water and allow to sit for 2-3 hours. When draining off the excess water, the dissolved salts will be removed along with the water.
This process can be repeated two or three times without any harm being done to the finished product.