Time-resolved two-color resonant four-wave-mixing spectroscopy was used to investigate collisions affecting the ground electronic state of the hydroxyl radical. Picosecond laser pulses provided adequate time resolution for measurements in an atmospheric-pressure methane-air flame. The grating spectroscopy technique used a combination of double resonance, time-delayed probing, and independent control of the polarization of each of the four fields involved in the wave-mixing process to enable measurement of the decay of laser-induced population, alignment, and orientation, as well as state-to-state transfer of these three moments. Results are presented for individual rotational levels of OH in X(2)II(3/2)(v=1).