Newbee wrote:Here is the link for coconut coir versus peat.
That is an excellent article!
http://flrec.ifas.ufl.edu/Hort/Environm ... ential.htm
Thanks for posting the link. If you have any more links to post from your own research about coir-dust/pith as a growing medium, please do post those links for everyone's benefit. Here (below) are some of my own thoughts and comments about coir pith, from my own experience during the last couple years.
Coir pith (coconut husk pith) as a growing medium ingredient for carnivorous plants
Although Sarracenia prefer sphagnum based mixes and grow better in them than in coir mixes, Venus Flytraps love coir mixes and grow great in them. However, the coir must be carefully prepared or it will damage or kill the plants.
First, the word coir is used for two different products: 1) chopped coconut husk fiber; 2) coconut husk pith which is removed from the fiber during processing and which was formerly regarded as a waste product in the production of fiber from coconuts for marine rope and other uses. I use the coconut husk pith, which I buy in compressed bricks or bales. There are several brands, but every brand I have bought has been the same material and looks as though it came from the same or similar source.
Here are several sources for compressed coconut husk pith, also known as coir--
My favorite source is the last one listed above.
Coconut husk pith or coir must be desalinated before use.
Ignore any manufacturers' or retailers' claims that their coir is low in mineral salts or soluble material. While the coir may not damage vegetable or flower gardens if used as a minor ingredient mixed with a lot of soil, it will almost certainly damage or kill plants when used as a primary ingredient in a soil mix, and this is especially true with plants that are sensitive to dissolved solids such as Venus Flytraps and other carnivorous plants. Much of the coir I have bought and used had an initial TDS (total dissolved solids) of over 1000 parts per million in the drained water from just the first soak of many! (under 50 parts per million is the suggested amount for carnivorous plants)
To desalinate coir, it can be soaked for 8-12 hours at a time, then drained and soaked with new distilled or other pure water, perhaps in 8-10 soak/drain cycles. A cheap TDS meter can be bought and used to determine when the drained water is consistently under 50 parts per million in total dissolved solids. At that time, the coir can be dried and stored, and the fluffy, dry coir can then be used as an ingredient in growing mediums mixed with other materials such as perlite and silica sand.
My usual coir growing mix so far, developed by experimentation and with an aim to mimic my favorite sphagnum-peat-moss based mix in water retentiveness and drying time between waterings is 12 parts dry, fluffy coir by volume to 5 parts silica sand. If I were to use perlite instead of silica sand, I would probably initially adjust the mix to include more perlite by volume: either 12 parts coir and 6 parts perlite, or 10 parts coir to 5 parts perlite.
A coir growing mix I'm experimenting with this year (2011) includes evergreen bark pieces ("orchid bark") in the mix.
In summary, coir (coconut husk pith, not coconut husk fiber) makes an excellent growing medium when mixed with other ingredients, but must be carefully prepared and desalinated first.
Best wishes, good growing and have fun!
(P.S. Newbee, I changed the title of your initial post to make it easier for others to search for and find this discussion in the future, since it is (in my opinion) an important and interesting topic. I hope that is OK.)