TurfCare 902971 GrowStar™ 20-00-10 50%XCU Bio 4%FE Fertilizer 50 lb provides gradual, steady nutritional uptake for up to 10 weeks of plant response. XCU® has the highest nitrogen (N) content (43%) and lowest sulfur content (4%) of any polymer-coated sulfur-coated urea (PCSCU) on the market. TCS GrowStar™ professional fertilizers are blended with the highest quality raw materials on the market, filtered three times before bagging to provide limited dust and formulated with the most innovative technologies to assure outstanding results.