Pumice is very porous and has a kind of abrasive surface texture. It is produced as a product of volcanic reactions. It absorbs and slowly releases fertilizers and as it drains well, it would be rather difficult if not impossible to over-water. This is another reason why pumice, especially of this size is suitable as a drainage layer; root rot can be avoided. Although roots cannot grow into pumice, just like Leca and stone, roots seem to like pumice and readily ramify in mixes which contain a fair amount of it.
Exceptional drainage characteristics
Helps mediums to retain structure
Lightweight and reusable
Porous, allowing for constant oxygen to roots.
How to use?
Bonsai: This medium size of Pumice is perfect as a bottom drainage layer in deep or larger pots where it is recommended that it be combined with the same particle size akadama to increase aeration in this zone and reduce the risk of root rot.
Orchids and Succulents: Ideal for orchids and larger succulents as it dramatically reduces the risk of root rot caused through excessive moisture. Aeration of the root zone is not impeded and as pumice does not degrade and collapse like bark, repotting intervals are greatly increased or not necessary. If additional moisture retention is needed then add some long fibred sphagnum moss.