Intensive vegetable farming can harm ecosystems, but using summer cover crops in northern climates can help. Researchers studied different cover crops in Minnesota and Wisconsin to see how they affected weed control and cash crop yield. They found that cover crops didn't always beat weeds, but less weedy plots had more overall plant growth. However, in one year, cover crops couldn't replace fertilizer for broccoli yield, leading to lower crop production. Overall, summer cover crops have potential to help northern farmers, but timing and weed control are important for success.