Green Up lawn sand contains ferrous sulphate and, in addition to controlling moss, gives lawns a healthy, rich green colour. Green Up Lawn sand is the traditional way to control moss throughout the Spring and Summer months (April to September). It should be applied at the recommended rates when the soil is moist. Seven to 10 days after application, the dead moss should be raked out of the lawn. This pack can treat 32 square metres of lawn. Total Nitrogen (N) 4.6% Iron (Fe), soluble in water 1.8% Always read the label on your purchased product before use.