Growing media (Rockwool)

Rockwool is a horticultural growing media made from the natural ingredients Basalt rock and Chalk. These are then melted at 1600° C into a lava which is blown into a large spinning chamber, which pulls the lava into fibers like "cotton candy." If you have ever visited a volcano you have probably seen these fibers flying around in the air surrounding the volcano. Once the fibers are spun they are then compressed into a mat which is then cut into slabs and cubes. The rockwool granulates are just bales of uncompressed fibers. The process is very efficient, producing 37 cubic foot of wool from 1 cubic foot of rocks. Since rockwool is born in fire it renders the product chemically and biologically inert and creates the ideal growing medium for hydroponics. Since its development in Denmark in the early 1970's, rockwool has become the major vegetable and flower production medium throughout Europe and North America.

Horticultural Rockwool growing media is primarily available in two general formats. First, as rigid slabs, blocks, and cubes known as "bonded" products because the fibers are held together with a "gluing" or binding agent which renders them stiff and brittle. This is the primary format for the vegetable and cut flower industries. Secondly, rockwool is available as a highly refined and consistent hydrophilic or hydrophobic granulate which is basically water absorbent or water repellent. This format can be used as a component in various peat moss based soilless media or for ground bed incorporation to improve the tilth of heavy clay or light sandy soils.