Lloyd - 4060 Monday, 05 September 2016
I raised this issue once with a radio gardening expert in Brisbane and my recollection is that these materials do lose their efficacy over time. Sadly I can"t recall the time frame. My assumption is that the material will still provide "bulk" to the garden that can be energised with added fertiliser.
I agree that there ought to be a "best by" date on such products.