Pumice is a light siliceous vesicular volcanic rock that is
suitable for use in horticulture and hydroponics. Its porosity
provides air spaces that maintain aerobic conditions around the
roots while water is contained within the pores. Surface tension
around the outside of theparticles increases water-holding
capacity of the growing medium. Ouris mined from a land based
resource, within 50kms of Lake Taupo in the North Island of New
Zealand, and it is characterized by its relative hardness and
lightweight in comparison to competing aggregates. The washing
and screening of our particularly for horticultural applications
means that no ‘fine’ particles are included. Unwashed can cause
‘concreting’ and higher water holding capacity than required,
consequently effecting root development. This hardness and
porosity allows free drainage lowering the risk of root-rot
diseases. Pumice grades supplied for horticultural uses include: