We report the growth of ZnSe/CdSe digital alloy quantum wells by migration enhanced epitaxy. The well regions are imbedded in barriers of ZnSe, and are composed of various periods of 1 monolayer (ML) of CdSe and 3 ML of ZnSe, thus having an effective Cd concentration of 25%. The time and sequence of successive shutter openings was varied during growth, and the effects on layer coverage were investigated using reflection high-energy electron diffraction oscillations, photoluminescence, photoluminescence excitation, and optical absorption.