This invention relates to hydroponic grass growth. Hydroponic grass is grown by forming a seed-bed, forming a supply of hydroponic nutrient solution including water and water-soluble phosphate plant nutrient, periodically withdrawing from the nutrient supply a quantity of solution in excess of that required to saturate the seed-bed and applying this excess quantity to the seed-bed, and draining the excess nutrient. The water used to form the hydroponic nutrient solution is pre-treated to separate impurity metal ions which form water-insoluble metal phosphates. The water-soluble phosphate plant nutrient is then dissolved in the pre-treated water to form the nutrient solution without the precipitation of impurity metal phosphates. Apparatus for growing the grass is also disclosed.
