Winter cover crops like barley and crimson clover can help reduce weed density by 50% in organic vegetable systems with reduced tillage. These cover crops also improve crop yield, especially for squash. The amount of cover crop biomass plays a key role in suppressing weeds and increasing crop yield. Mixing different cover crops or using them alone has similar effects on weed control and yield improvement. Overall, using winter cover crops in reduced tillage systems can be an effective strategy for organic crop production.