\'Recommended organic garden product - The Times Moss, mould, algae they all love hard surfaces, clinging and causing damage to pathways, patios and decking; turning them into slippery, hazardous messes. RHS Natural Moss Killer dismisses them quickly and effectively using natural ingredients (kinder to the environment than conventional based killers) which once dried are harmless to children, pets and wildlife. No bleach, no harsh chemicals, no staining and no damage to surfaces. Results within hours! Use all-year round. 1L covers 35sq m. 5L covers 175sq m.