We are putting down new lawn and have dug up all the top soil only to find clay beneath it. Have been told that gypsum will break the clay down .. how much do we throw down? Have purchased gypsum - yellowish in colour .. is this gypsum or are there different varieties of gypsum.
23 October 2019 08:23 AM
There may be some slight colour variation in gypsum but basically there is only one type of gypsum, calcium sulphate dihydrate. For best results, we suggest you dig up the clay to a depth of 15 cm, breaking up any large clumps, then spread gypsum at a rate of 1 - 2 kg per square metre. Work into the top of the soil and water in well.