Landscape fabric, often called a weed barrier, is a permeable textile material designed to be laid over soil to manage plant growth. Its primary function is weed suppression, achieved by blocking the sunlight needed for weed seeds to germinate and grow. Beyond weed control, this barrier helps conserve soil moisture by reducing water evaporation from the ground surface. The fabric also provides a measure of erosion control, particularly on slopes, by holding the soil in place against heavy rain or wind.
Preparing the Site and Selecting Materials
Effective installation of a weed barrier begins with thorough preparation of the area before the fabric is unrolled. Preparation involves clearing all existing vegetation, especially perennial weeds, by removing the entire plant, including the roots. For stubborn weeds that spread through underground runners (rhizomes or stolons), digging out every piece is necessary, or a non-selective herbicide application may be used for complete eradication.
The soil surface must be cleared of any sharp objects like rocks, sticks, or construction debris that could tear the fabric. Incorporate any soil amendments, such as compost or fertilizer, at this time, since the fabric will restrict access to the soil afterward. Finally, rake the soil smooth and flat. This ensures the fabric rests flush against the ground and prevents air pockets or uneven spots where water might pool.
Selecting the appropriate material requires distinguishing between woven and non-woven fabrics. Woven fabric, made from tightly interlaced polypropylene fibers, offers superior durability and tensile strength, making it the preferred choice for areas with heavy foot traffic or under gravel paths. Non-woven fabric is a bonded material that offers better water permeability and is more flexible for irregularly shaped garden beds. For most planting beds, high-quality woven fabric is suitable, balancing effective weed control with the necessary allowance for water and air exchange.
Securing the Fabric to the Landscape
Unroll the fabric across the prepared area, starting from one edge and allowing it to follow the natural contours of the soil. The material must lay flat against the surface and should not be stretched taut over dips or bumps, which prevents weeds from finding space underneath. If multiple sections are required, a generous overlap is necessary to create a continuous barrier.
Adjacent strips must overlap by a minimum of six inches, or up to twelve inches in areas with high weed pressure. This overlap prevents sunlight from reaching the soil at the seam, a common point of failure. Secure the overlapped edges and the perimeter using U-shaped landscape staples or pins.
Drive these fasteners into the ground with the top flush with the fabric surface, placing them every eight to twelve inches along all seams and perimeter edges. In the main body, insert staples every one to three feet to prevent the material from shifting or ballooning in the wind. For areas with loose or soft soil, placement should be more frequent to ensure the fabric remains firmly anchored. Trim the fabric to fit around borders or walkways after it is fully secured, using a sharp utility knife to make precise cuts that tuck slightly under the edging.
Cutting Openings and Applying Ground Cover
When planting is necessary, cut openings into the secured fabric with precision to minimize the exposed soil area. For new plants, use an X-shaped incision or a small circular cut, just large enough to accommodate the root ball. After planting, pull the fabric flaps back snugly around the base of the stem.
Secure the fabric flaps close to the plant base with an additional landscape staple to prevent weeds from emerging. For existing plants, slit the fabric from the edge to the center, then lay it around the stem, ensuring the cut is tight against the trunk or stem. Immediately cover the landscape fabric with the chosen ground cover material.
This covering (organic mulch, gravel, or stone) serves the dual purpose of protecting the fabric and suppressing weeds. Ultraviolet (UV) light causes the fabric to degrade, so a layer of ground cover shields the material and extends its lifespan. For organic mulches like wood chips, a depth of two to three inches is recommended to block weed seeds that may settle on top. If using inorganic material such as decorative stone or gravel, a layer of one to two inches is sufficient to protect the fabric and keep it in place.