Method for making a synthetic turf comprising laying a turf (1) consisting of a mat (2) on which a plurality of blades (3, 3a, 3b, 3c) of synthetic material is woven. An infill material (18) is obtained using the granular and fibrous part (17) of a loose product based on ground coconut, alone or with addition of other material such as rubber in granules or sand or other loose vegetable material such as cork. The raw material based on coconut, having a heterogeneous granulometry set between about 500 micron and several mm, is obtained loading a loose product based on ground coconut by a hopperon a conveyor belt for being fed in a sieve, for example a rotating screen that separates the powder part from the granular and fibrous part. In particular, the powder part of the raw material, is gathered on a conveyor belt and from here sent to a storage reservoir. The granular and fibrous part of the raw material, which represents the main product of the process, is, instead, sent by a conveyor belt to a storage, reservoir from where it is taken for the process to provide infill material for a synthetic turf.