Product Information

Each plug is 40mm x 40mm x 40mm

Each plug is sold individually



Rockwool is a horticultural growing media made from the natural ingredients Basalt rock and Chalk. The most important characteristic of all formed rockwool lies in the fact it allows growers to quickly respond to fluctuations in the plant's rooting environment.


The rockwool being an inert media means that rockwool fibers do not modify or restrict the availability of nutrient to the plants. Due to this zero Cation Exchange Capacity (CEC), the material can be leached of all fertilizer "salts." In addition to this, rockwool possesses a near-zero absorption capacity for water, thus allowing more water to be available to the plants when compared to production in soilless media.


Of the total amount of nutrient solution applied to a rockwool slab, only 2% is unavailable for plant uptake. Organic media such as peat moss and sawdust, possess a 65% water holding capacity and nearly 4-8% of the nutrient solution is absorbed to the colloidal structure of the material and hence is unavailable to the plants. Due to the unique pore structure of the rockwool, it can safely receive large volumes of nutrient solution without leaving it water logged.


After excessive soaking, the slab, block or cube will drain sufficiently, in a short period of time, so that 40-50% of the pore space is occupied by air. Deliberate leaching of the slab with excessive nutrient solution can be used as a management tool to control crop health and maintain optimum growing conditions in the root zone.

Rockwool Starter Plugs