A flexible hose for transporting a fluid, particularly a flexible garden hose for transporting water, includes an inner layer made of a first elastic polymeric material; an outer layer made of a second elastic polymeric material; and a textile reinforcement layer interposed therebetween. The inner and outer layers are reciprocally coupled to form a unitary tubular member, internally to which the textile reinforcement layer is embedded. The elasticity of the unitary tubular member causes it to automatically enlarge under the working pressure given by the liquid flowing therethrough to increase its original diameter and to automatically recover to assume again its original diameter once the working pressure stops. The textile reinforcement layer is susceptible to move from a rest configuration, when there is no working pressure, to a working configuration, when the unitary tubular member enlarges upon under the working pressure.