This work reports on accurate, high-resolution measurements of the 25 Mg (n, γ) 26 Mg and 25 Mg (n, tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved 25 Mg (n, γ) 26 Mg parametrization. The relevant resonances for n+ 25 Mg were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in 26 Mg. With this information experimental upper limits of the reaction rates for 22 Ne (α, n) 25 Mg and 22 Ne (α, γ) 26 Mg were established, potentially leading to a significantly higher (α, n)/(α, γ) ratio than previously evaluated. The impact of these results has been studied for stellar models in the mass range 2 to 25 M⊙.