Weed control in organic soybean usually includes frequent pre-plant tillage operations but spring rains often make it difficult to get into the fields for timely tillage. As a result, weed pressure can be high. Cover crops can help suppress weeds, but after corn harvest it is often too late to establish cover crops. Spring-planting cover crops may be an alternative to fall-planting. In this study, our objective was to test the effectiveness of cool-season cover crops in suppressing weeds before and after soybean planting.