Liquid Seaweed Fertiliser (Donegal Seaweed) - 20LGarden Force seaweed extract is especially useful in organic gardening. It contains almost every micro nutrient in a fully chelated (immediately available) form. The algae are also full of carbohydrates, which plants use as a building block. Numerous beneficial microorganisms also use carbohydrates as a food source. Seeds soaked in Garden Force seaweed extract germinate more rapidly, have larger root mass, stronger plant growth, and higher survival