Abstract: A coated or encapsulated granular fertilizer which comprises an olefin polymer and/or copolymer and a polyether polyol in a defined amount. The olefin polymer is an ethylene or propylene homopolymer and/or a copolymer of an olefin monomer and a copolymerizable monomer such as olefinic monomers, vinyl acetate and carbon monoxide. The polyether polyol is polymers of ethylene oxide, propylene oxide and mixtures thereof with or without etherification with polyhydric alcohols. By the addition of the polyether polyol, a dissolution rate of the fertilizer can be arbitrarily controlled without a sacrifice of physical properties of the coated film.