Sulfate of Potash, also known as Potassium Sulfate, is a potent source of the vital macronutrient Potassium without the harmful chlorides often found accompanying it. Boasting a whopping 50% Potassium content and 17% Sulfur content, Potassium Sulphate is very effective at promoting a strong flowering and fruiting cylce in plants. You can also expect to see greater resistance to pests and diseases as well as improved and expedited ripening of fruits. Potassium is second only to Nitrogen in the amount used by plants. So, ensuring plenty of available Potassium is vital to ensuring a healthy and successful crop.