The nonlinear propagation characteristics of Gardner solitons (GSs) in a non-planar (cylindrical and spherical) two-ion-temperature unmagnetized dusty plasma, whose constituents are inertial negative dust, Boltzmann electrons and ions with two distinctive temperatures, are investigated by deriving the modified Gardner (mG) equation. The standard reductive perturbation method is employed to derive the mG equation. The basic features of non-planar dust-acoustic (DA) GSs are analyzed. It has been found that the basic characteristics of GSs, which are shown to exist for the values of ni10/Zdnd0 around 0.311, for ni20/Zdnd0 = 0.5, Ti1/Te = 0.07, and Ti1/Ti2 = 0.05 [where ni10 (ni20) is the lower (higher) temperature ion number density at equilibrium, Ti1 (Ti2) is the lower (higher) temperature of ions, Te is the electron temperature, Zd is the number of electrons residing on the dust grain surface, and nd0 is the equilibrium dust number density] are different from those of Korteweg-de Vries solitons, which do not exist around ni10/Zdnd0 ≃ 0.311. It has been found that the propagation characteristics of non-planar DA GSs significantly differ from those of planar ones.