Landscape fabric, often called a weed barrier, is a permeable material designed to suppress the growth of unwanted plants in established garden beds. Its primary function is to block sunlight from reaching the soil, which prevents weed seeds from germinating and growing. The fabric also plays a role in conserving soil moisture by significantly reducing the rate of evaporation from the surface. Integrating this barrier into an existing landscape requires a careful, methodical approach to ensure the material performs its function without harming the plants already in place.
Preparing the Planting Bed
The effectiveness and longevity of the fabric depend heavily on the initial preparation of the soil surface. Before the first roll of fabric is laid down, the entire area must be thoroughly cleared of all existing vegetation. This includes digging out all weeds and grass, paying particular attention to perennial weeds with deep or extensive root systems.
Failing to remove these root structures means resilient weeds may still attempt to push through the material, compromising the barrier’s integrity. Once the vegetation is removed, the ground should be raked smooth to eliminate debris. Removing small stones, sharp twigs, or uneven soil clumps is necessary because these objects can puncture or tear the fabric during installation.
A smooth, level surface is paramount for ensuring the fabric maintains consistent contact with the soil. This uniformity prevents air pockets from forming underneath, which could allow weed seeds to germinate in trapped soil or moisture. It is also beneficial to trim back any low-hanging foliage from existing shrubs or trees so they do not interfere with rolling out the material.
Techniques for Fitting Fabric Around Stems
Installing the fabric around established plants is the most intricate part of the process and requires precise cutting to maintain the barrier’s weed-blocking capability. For larger shrubs and trees, the Slit Cut method is the most practical way to maneuver the fabric into position. This involves starting the roll of fabric at the edge of the bed and rolling it until it encounters the plant’s trunk or main stem.
At this point, a straight line is cut from the outer edge of the fabric inward toward the center of the plant. This slit should extend just past the center of the stem, allowing the fabric to be slipped around the plant and laid flat on the ground. Once the fabric is in place, the slit is brought back together, creating a snug fit around the base of the plant.
For smaller, more flexible plants or those with a small crown, the X-Cut or Hole Punch method offers a more secure fit. The fabric can be laid directly over the smaller plant, and a small “X” or circular incision is made directly above the stem. The goal is to make the cut just large enough for the plant to pass through without tearing the fabric unnecessarily.
After the incision is made, the plant is gently fed through the opening, allowing the fabric to settle flush against the ground. Minimizing the size of these cuts is important, as any excess opening becomes a pathway for weeds to emerge. The material should fit snugly against the stem, leaving as little exposed soil as possible.
Securing the Barrier and Applying Groundcover
Once the fabric is cut and positioned around all existing plants, secure it firmly to the ground to prevent shifting. If the area requires more than one width of fabric, the sheets must be overlapped by a minimum of 6 to 12 inches to create a continuous barrier. This overlap prevents weeds from growing up through the seams where the two pieces meet.
The fabric is held in place using U-shaped landscape staples or pins, driven through the material and into the soil below. These staples should be placed along all edges and particularly along the overlapping seams, with a recommended spacing of 12 to 24 inches. Securing the perimeter prevents the edges from lifting due to wind or ground movement.
The final step is to immediately cover the entire surface of the landscape fabric with a layer of groundcover, such as organic mulch, shredded bark, or decorative gravel. A layer of 2 to 3 inches is recommended. This covering is not merely for aesthetics but serves the practical function of shielding the underlying fabric from ultraviolet (UV) light.
Most synthetic landscape fabrics will rapidly degrade, becoming brittle and tearing, when exposed to continuous sunlight. The protective groundcover extends the material’s lifespan significantly, ensuring the weed barrier remains effective. It also helps hold the fabric down and regulates the soil temperature for the established plants.