Garden edging acts as a defined boundary between distinct landscape elements such as a lawn, a garden bed, or a walkway. This separation enhances the visual structure of an outdoor space and provides practical containment. Edging physically prevents materials like mulch or topsoil from migrating into adjacent areas, maintaining a clean appearance. It also helps inhibit the lateral spread of turfgrass roots into planting beds, reducing maintenance efforts.
Selecting the Right Edging Material
The choice of material significantly dictates the aesthetic and long-term performance of the boundary. High-density polyethylene or polypropylene plastic edging offers great flexibility for creating smooth curves and is typically the most budget-friendly option. Longevity depends on quality; cheaper options without UV stabilization can become brittle and crack when exposed to solar radiation. Quality plastic provides respectable durability and is very low maintenance once installed.
Metal edging, typically aluminum or steel, provides a sleek, thin profile that creates professional, crisp lines. Aluminum is favored for its natural resistance to corrosion and is malleable enough for curved designs. Steel, especially Cor-Ten or galvanized steel, offers maximum strength and longevity, often lasting for decades with virtually no maintenance. The primary trade-off is a higher initial cost and potential for corrosion in untreated steel, though powder-coating mitigates this risk.
Natural stone, bricks, or concrete pavers offer a classic, permanent aesthetic and are among the longest-lasting options available. These materials are highly durable, easily withstanding heavy foot traffic and freeze-thaw cycles. However, they are the most expensive per linear foot and often require more complex preparation, such as a compacted gravel and sand base, to ensure stability.
Wood, often in the form of treated timber or landscape ties, provides a warm, organic look that complements natural settings. While initially cost-effective, wood requires the most maintenance to prevent rot, decay, and insect damage. Even pressure-treated wood will eventually degrade, meaning its lifespan is significantly shorter than metal or stone.
Preparation and Layout of the Edging Site
Precise preparation of the site is necessary to ensure the final installation is straight, stable, and visually appealing. The first step involves clearly defining the intended line of the edging, whether straight or curved. A garden hose or a string line pulled taut between stakes works well for outlining the path, allowing for visualization and measurement before breaking ground.
Once the line is marked, measure the area to calculate the exact quantity of material needed, accounting for waste or overlap. All existing debris, turfgrass, and rocks should be cleared along the marked path to create a clean, even surface. This clearing prevents future shifting of the material due to underlying obstructions.
Dig a narrow trench along the designated line using a flat spade or a trenching tool. The depth is determined by the material; for most flexible plastic or metal edging, three to six inches is common, allowing the top edge to sit slightly above or flush with the ground. Save the excavated soil, as it will be used later for backfilling and securing the material.
Step-by-Step Installation Techniques
With the trench prepared, begin installation by positioning the first section of edging material. For coiled materials like plastic or metal strips, unroll them and let them sit in the sun to relax, making them easier to handle and straighten. Set the material into the trench, ensuring it presses firmly against the established wall of the cut.
When working with materials that come in sections, joining them correctly is necessary to maintain structural integrity. Metal edging often uses interlocking ends or separate connector plates, which should be secured before the strip is completely set. For plastic edging, a coupler is typically slid over the meeting ends, ensuring a secure, continuous run.
Securing the edging is accomplished using stakes, which provide resistance against soil pressure and movement. Metal edging requires steel spikes driven through pre-drilled holes, usually every one to two feet, angled slightly toward the garden side for maximum stability. Plastic edging uses landscape stakes, often made of plastic or composite, which are hammered in near the top edge, securing the material against the trench wall.
For rigid materials like pavers or stone, a solid base is required instead of a simple trench. The excavated area needs a compacted layer of gravel or crushed stone, typically four to six inches thick, followed by a thin layer of bedding sand. Pavers are laid directly onto this sand base, adjusted for level, and often secured laterally with a plastic or metal edge restraint system spiked into the sub-base.
Backfill the trench using the soil saved during the excavation phase. Soil should be packed tightly on both sides of the edging, starting with the outer side to push the material firmly against the garden bed. Using a hand tamper or stomping along the edge helps to compact the soil and lock the edging securely in place, preventing future shifting.
Final adjustments involve checking the entire run with a spirit level or a taut string line to confirm the top edge is uniform in height and alignment. For metal or plastic, this may involve adding or removing soil and re-tamping. A final watering of the backfilled soil assists in settling the material, revealing any low spots that require further compaction or additional soil.