The material, used primarily in slab form, has to be disposed of after several cropping periods as its water retention characteristics change. The medium will contain the concentrations and mix of plant nutrients found in the irrigation water. There are currently no recycling or recovery options available to greenhouse growers in BC for the disposal of rockwool. Reduction in the volume of waste substrate generated is the most effective option available to the grower for handling the waste materials. Reduce the amount of rockwool used for plant growth.
Research indicates there are possibilities for less waste production without yield losses.
Rotate crops to reduce or eliminate the risk of pathogens in re-used rockwool substrate. Rockwool slabs can function effectively for three to four years without replacement. Limit quantities applied so as not to visually impair the appearance of the soil. Where a sufficient land base is not available to a greenhouse grower, the rockwool should be removed to a municipal landfill. Do not bury waste rockwool substrate on private property.