Landscape fabric is able to prevent weeds by limiting access to sunlight and space that weeds need to grow. When laid over the soil, the fabric blocks light from reaching weed seeds beneath the surface, which stops most of them from germinating. At the same time, the fabric’s porous design allows air, water, and nutrients to pass through. This keeps the soil underneath healthy for plants that you want to grow.
Weeds that try to sprout above the fabric struggle to root into the ground because the material separates the soil from the top layer of mulch or gravel. Over time, this reduces the number of new weeds and makes any that do appear easier to pull out. The effectiveness of landscape fabric depends on proper installation, such as overlapping seams and securing edges, to prevent weeds from finding gaps to grow through.
