I bought coconut coir as Mulch Bricks to mix into my veggie containers a few years back because they were cheap, I thought they might help with water retention, and I believed the hype about how coir was better to use than peat. The small brick did indeed expand to two cubic feet. But the chunks were 1 to 2 inches in diameter, and I don't believe they helped with drainage because my other soil components were so much smaller. Also, I would be concerned about the fact that this stuff is "colored." unless the label says it's safe for use on veggies, I wouldn't use it on anything you're going to eat. I also understand that coir can contain a lot of salts. Now I am using Al's 511 mix with pine bark fines. They are actually cheaper and have worked very well for me. Check the link if you want to know more. Here is a link that might be useful: Container Soils -- Water movement and retention

Sphagnum peat and coir have nearly identical water retention curves. They both retain about 90-95% of their volume in water at saturation and release it over approximately the same curve until they both lock water up so tightly it's unavailable for plant uptake at about 30-33% saturation. Coir actually has less loft than sphagnum peat, and therefore, less aeration. Because of this propensity, coir should be used in mixes at lower %s than peat. Because of the tendency to compact, in the greenhouse industry coir is primarily used in containers in sub-irrigation (bottom-watering) situations. Many sources produce coir that is high in soluble salts, so this can also be an issue. Using coir as the primary component of container media virtually eliminates lime or dolomitic lime as a possible Ca source because of coir's high pH (6+). Gypsum should be used as a Ca source, which eliminates coir's low S content. All coir products are very high in K, very low in Ca, and have a potentially high Mn content, which can interfere with the uptake of Fe. Several studies have also shown that the significant presence of phenolic allelochemicals in fresh coir can be very problematic for a high % of plants, causing poor growth and reduced yields. I haven't tested coir thoroughly, but I have done some testing of CHCs (coconut husk chips) with some loose controls in place. After very thoroughly leaching and rinsing the chips, I made a 5:1:1 soil of pine bark:peat:perlite (which I know to be very productive) and a 5:1:1 mix of CHCs:peat:perlite. I planted 6 cuttings of snapdragon and 6 cuttings of Coleus (each from the same plant to help reduce genetic influences) in containers (same size/shape) of the different soils. I added dolomitic lime to the bark soil and gypsum to the CHC soil. After the cuttings struck, I eliminated all but the three strongest in each of the 4 containers. I watered each container with a weak solution of MG 12-4-8 with STEM added at each watering, and watered on an 'as needed basis', not on a schedule. The only difference in the fertilizer regimen was the fact that I included a small amount of MgSO4 (Epsom salts) to provide MG (the dolomitic lime in the bark soil contained the MG, while the gypsum (CaSO4) in the CHC soil did not. This difference was necessary because or the high pH of CHCs and coir.) for the CHC soil. The results were startling. In both cases, the cuttings grown in the CHC's exhibited I just find it very difficult for a solid case to be made (besides "It works for me") for the use of coir or CHC's. They're more expensive and more difficult to use effectively. The fact that some believe peat is in short supply (no where near true, btw) is easily offset by the effect of the carbon footprint of coir in its trek to the US from Sri Lanka or other exotic locales. That's the view from here. YMMV Coir Study: https://sites.google.com/site/plantandsoildigest/usu-crop-physiology-laboratory/coconut-coir-studies Al

no no no! no garbage can! rule of universe: everything you throw out you have to pay money to replace. Spray it clean with a high-pressure nozzle on your water hose, & you can put it in the bottoms of pots, soak it thoroughly & use it to start seeds or cuttings, use it for mulch, shred it & hang shreds on your fences for the birds to make their nests.

Dear Rersoap, I sometimes use a seed starter mix to start seedlings for hydroponics. Some gardening programs on TV advocate using coconut coir mixed with fine sand for starting seedlings. I buy most of my seedlings from Plant Nurseries, and sometimes plant the seeds directly into my coarse sand medium. What is important, is to wash all of the seed raising mix, whether commercially grown or home-made coir and sand from the seedling's roots before planting out into the hydroponic medium. This helps to keep the medium clean. Please have a look at my web site from Australia. It will tell you just about everything you need to know about hydroponics, except lighting systems which we do not need, as we have ample sunlight all year round. Jimr007 Australia. Here is a link that might be useful: Simple Sand Hydroponics