About 18 months ago the Brazilian government banned the sale of tree fern fiber pots ( my favorite medium) as so many plants were being destroyed from the wild and recommended growers switching to coconut fiber. Since then I have been repotting most of my orchids into the latter. I have noted however a substantial number of them failing to thrive. I discussed this with a fellow grower who also uses coconut fiber pots and she reported similar problems.
Subsequently I discussed this with a well-known plant nutritionist. He informed me that coconut fiber contains a large amount of taurine, a substance not common in plant fibers. Although this was capable of being removed by thorough washing, he thought that probably many producers failed to do this. As he regarded the presence of taurine in orchid compost as suspicious he recommended me no longer to use coconut fiber.
I now face a considerable dilemma. I'm very reluctant to go back to using plastic or clay but feel there is no viable organic alternative. I would like to know what experiences other growers have had with using coconut fiber. I don't regard it as a proven guilty case just yet. If it is to be regarded with suspicion, however, what alternatives are there? I have found an (illegal) supplier of tree fern pots but supplies are very limited and this will not be a long term answer.
