Pumice is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. It is typically light colored. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano. The unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization.
Pumice is an excellent soil conditioner, as it is highly porous, giving it excellent water and air holding properties. Advantages of using pumice for potting orchids with pumice include:
- the porous nature of pumice allows it to hold vital nutrients in the microscopic surface pores, which helps regulate fertilizer feedings.
- excellent conditioner for soils that need increased aeration and drainage, as when growing tropical plants like anthuriums, philodendron and orchids.
- loosens the density of rotting bark, letting in the air and water plants need.
- increases water retention in dry and very airy bark.
- holds moisture in the sundries, reducing watering requirements, yet pumice will not compact or become soggy.
- pumice is inorganic, so it will not decompose or compact over time, meaning it functions continuously and can be recycled and reused.
- pumice is pH neutral.
- pumice does not attract or host fungi, nematodes, or insects.
An addition of max. 10% to your sundries is enough to have all the benefits from quality pumice.