Roof Gardens and Green Roofs
J. Arthur Bower's Hydroleca is a lightweight clay aggregate formed by special clay minerals expanded at high temperature. This produces ceramic "pebbles" with a smooth outer crust and a honeycomb interior. These pebbles are sterile, non-toxic, inert, resistant to algae, extremely strong and can absorb up to 40% of their own weight in water. They are not damaged by frost and have good insulating properties.
In order to make the growing media lighter, mix in one part Hydroleca with three parts compost. This mix can be used in both containers and raised beds.
Hydroleca can be used as the drainage layer in green roofs. We recommend using a pre-planted vegetation mat.