AbstractNear‐optimal multiperiod decision rules for controlling wild oats in spring wheat in north central Montana are presented in this paper. Decision alternatives are fallow, use of a preemergent or postemergent herbicide, and crop without use of a herbicide. The near‐optimal decision rules, which were obtained from a partially decomposed stochastic dynamic programming model, depend on density of wild oats seed in the plow layer, whether the land was previously cropped or fallow, soil moisture level, price of spring wheat, and post‐planting density of wild oats.