In the three sisters, which component primarily helps suppress weeds by covering the soil?

• A. Corn stalks
• B. Beans
• C. Squash vines
• D. All three

Answer: (C)

The main idea here is how a ground-covering crop helps keep weeds from taking over a garden or field. In the Three Sisters planting, squash vines spread across the soil with broad leaves that blanket the ground. This shading and the living mulch they create suppress weed growth by blocking sunlight that weed seeds need to germinate, and by keeping the soil moist and less hospitable to competing plants. So, the squash acts as the primary weed suppressor through its direct coverage of the soil.

Meanwhile, corn provides a tall structure for beans to climb, and beans contribute nitrogen to the system, but neither directly covers the ground to the same extent or shade it as effectively as the squash. Together, they support the garden’s health, but the ground-covering effect that most strongly reduces weeds comes from the squash vines.