Magnesium is very essential for Photosynthesis and maintaining healthy, green plant growth. Magnesium helps to improve seed germination and strengthen cell walls, leading to strong seedlings. Magnesium also improves flavor, sweetness and nutritional quality of fruits & vegetables. A lack of magnesium causes a general loss of green colour between the veins of leaves and becomes more evident in older leaves. Yellowing of plant tissue rapidly increases resulting in premature defoliation. Magnesium deficiency causes yellowing of older leaves with veins remaining green. Manutec EPSOM SALT (Magnesium Sulphate) is completely soluble in water and quickly corrects the deficiency in soils and pots. Directions For Use Dissolve 10g (2 level measures of enclosed spoon) to each litre of water. Water the plant as normal. For plants with severe deficiencies, repeat the application every 4 weeks until a positive response is evident.