Professional grower mixes are light fluffy mixes for all plants. They promotes good root structure for strong healthy plants. Our professional blend goes three steps further to further benefit your plant growing experience. It contains Worm Castings, Mycorrhizal Fungi, & Humic Acids. The worm castings not only contain vital nutrients, but many beneficial microorganisms. These microbes and the mycorrhizal fungi together help plants take up nutrients, fight off deadly pathogens, grow stronger roots and improves the structure of the soil. Humic acids are able to help plants in many ways, they stimulate proliferation of beneficial fungi & other soil microbes, stimulate root and plant growth, increases vitamin content of fruits and vegetables, increase water holding capacity and at the same time improve aeration of the soil, prevents leaching of water-soluble fertilizers, and help plants take up nutrients. 3.5 Litre bag for $12 2 Litre bag for $7 Ask for pricing for 12 Litres or more. Ingredients; Organic Perlite, Organic Peat, Vancouver Island Ground Fir Bark, Organic Worm Castings, Food Grade Diatomaceous Earth Powder, Leonardite Powder w/Humic Acids, Dolomite, & Mycorrhizal Fungi