Resonant soft x-ray scattering experiments with photon energies near the O K and the Cu L₃ edge on the system La_1.8-xEu _0.2Sr_xCuO₄ for 0.1≤x≤0.15 are presented. A phase diagram for stripelike charge ordering is obtained together with information on the structural transition into the low-temperature tetragonal phase. A clear dome for the charge ordering around x=18 is detected well below the structural transition. This result differs substantially from other systems in which static stripes are detected. There the charge order is determined by the structural transition appearing at the same temperature. Furthermore, we present results for the coherence length and the incommensurability of the stripe order as a function of Sr concentration.