Mykos Wettable Powder is for use on established plants. Simply mix with water and apply around the base of each plant. Also great for use in hydroponic reservoirs. Mykos is very-specific specie of Mycorrhiza that works faster and stronger. If you haven't heard of mycorrhiza, it's a microbe that builds root mass and increases plant uptake of nutrients and water. With more roots, you get more fruits. Mykos is a beneficial additive; it may be used with any nutrient line. Great for vegetables, fruits, flowers, & herb. Some sizes may not be stocked in all locations.