This invention relates to a coating composition for a fertilizer comprising at least 50 wt% of a cross-linked lipid; and less than 0.20 wt%, relative to the total weight of the lipid, of a catalyst for cross-linking an unsaturated lipid. The cross-linked lipid has a viscosity at 20 degree Celsius (°C) in the range of 110 and 800 mPa.s.