Landscape fabric is a permeable barrier used primarily for weed suppression and soil separation. While often marketed as low-maintenance, its effectiveness depends entirely on the specific application. Used correctly, it saves time in long-term installations, but when misplaced, it can actively hinder plant health and complicate maintenance. Understanding its appropriate use is key to successful landscape design.
Appropriate Applications for Landscape Fabric
Landscape fabric provides the most lasting benefit in permanent installations where soil health and frequent planting are not primary concerns. The fabric acts primarily as a separation layer, preventing materials like decorative stone or gravel from sinking into the underlying soil. This function is particularly helpful under gravel paths, where it maintains a stable base for foot traffic and keeps the gravel clean.
The material is also well-suited for use under hardscaping projects, such as paver patios or flagstone walkways, where it stabilizes the base layer. Installing a professional-grade geotextile fabric helps prevent the base material from mixing with the subsoil, which is crucial for long-term stability and proper drainage. The fabric can also be used behind retaining wall backfill to prevent fine soil particles from migrating into the drainage layer, ensuring the wall functions correctly.
In these applications, the fabric’s primary role is engineering, not gardening, which bypasses many common drawbacks. It is also an effective choice for a base layer under permanent playground surfaces, such as wood chips or rubber mulch, where it suppresses weeds and separates the surfacing material from the ground. For these high-traffic, non-planting areas, the fabric delivers a structural benefit difficult to replicate with organic materials alone.
Situations Where Fabric Should Be Avoided
Using landscape fabric in planting areas, such as perennial beds, annual flower beds, or vegetable gardens, often leads to long-term issues that outweigh short-term weed suppression. The fabric creates a physical barrier that prevents organic mulch, like wood chips or shredded leaves, from decomposing and incorporating into the soil structure. This blockage starves the soil of organic matter, which is important for microbial activity and nutrient cycling.
Over time, soil and fine debris accumulate on top of the fabric, even when covered with mulch or stone. Wind-blown seeds land in this thin layer and germinate, leading to weeds that root directly into the fabric itself. Removing these weeds is significantly harder because the roots become tightly entwined in the weave, often requiring the fabric to be torn.
Hindering Soil Health
The fabric also restricts gas exchange between the soil and the atmosphere. This restriction leads to soil compaction and a lack of oxygen for plant roots and beneficial organisms like earthworms.
For areas requiring frequent maintenance, such as vegetable gardens or perennial beds where plants are divided or moved, the fabric is counterproductive. Any digging, tilling, or soil amendment requires cutting the fabric, which compromises its integrity and creates weak points for weed growth. The fabric also limits the natural expansion of root systems and hinders the ability to top-dress with compost or fertilizer, affecting the long-term health of garden plants. For areas with aggressive weeds like nutsedge or horsetail, the fabric is not a permanent solution, as these plants can puncture or grow around the material, making subsequent removal more difficult.
Essential Ground Preparation and Fabric Selection
Proper preparation is essential to ensure the landscape fabric functions as intended in appropriate applications. Before laying the fabric, all existing weeds, grass, rocks, and debris must be completely cleared. It is important to remove the roots of persistent weeds, as they may otherwise grow through the material.
The ground should be raked and leveled to create a smooth surface. Sharp objects can puncture the fabric, and an uneven base can cause the top layer of mulch or stone to shift. If soil amendments are required, such as compost, they must be worked into the soil before the barrier is laid, since the fabric prevents top-down incorporation later.
Selecting the correct type of fabric is important for success. Once laid, the fabric sheets must be overlapped by six to twelve inches to prevent weeds from growing through the seams and secured to the ground using landscape staples or pins.
Types of Landscape Fabric
There are two primary types of fabric:
- Woven landscape fabrics, typically made from polypropylene, offer superior durability and are best suited for high-traffic areas like paths or under permanent hardscapes due to their strength.
- Non-woven fabrics, which have a more felt-like texture, are better for applications requiring filtration, drainage, or erosion control, such as behind retaining walls or on slopes.