Landscape edging is a fantastic way to define garden beds, walkways, and other outdoor features, providing a clean, polished look while preventing grass and weeds from encroaching into unwanted areas. But the aesthetic appeal is only half the story. What you put under your landscape edging is just as crucial, impacting its stability, longevity, and overall effectiveness. Choosing the right material beneath your edging is vital for ensuring a beautiful and functional landscape for years to come.
Why the Sub-Base Matters for Landscape Edging
The foundation beneath your landscape edging is more than just filler. It acts as a support system, preventing shifting, sinking, and the eventual degradation of your edging material. Think of it as the bedrock upon which your landscape design rests. Without a proper sub-base, even the most expensive edging will become uneven, ineffective, and unsightly over time.
A well-prepared sub-base provides several key benefits. It enhances drainage, preventing water from pooling and eroding the soil around the edging. It creates a stable foundation, resisting the natural settling and shifting that occurs with temperature changes and ground movement. This stability directly translates to a longer lifespan for your edging and a more attractive landscape overall. Furthermore, the right sub-base can help prevent weed growth, minimizing the need for constant maintenance.
Exploring Sub-Base Material Options
Selecting the appropriate material for your sub-base is a critical decision. The best choice depends on several factors, including the type of edging you’re using, the soil conditions in your yard, and your budget. Let’s delve into some popular and effective options.
Gravel: The Workhorse of Landscape Edging Foundations
Gravel is a widely used and highly effective sub-base material. Its excellent drainage properties and ability to compact firmly make it an ideal choice for supporting a variety of edging types. Different types of gravel are suitable for different needs.
Crushed Stone: A Solid Foundation
Crushed stone is a great choice for a sub-base because of its angular shape. The sharp edges interlock, creating a very stable and compacted base that resists movement. This stability is especially beneficial for heavier edging materials like concrete or stone. When selecting crushed stone, consider the size of the aggregate. A mixture of sizes, often referred to as “crusher run” or “dense grade aggregate,” is ideal as it compacts effectively and provides excellent support.
Pea Gravel: For Better Drainage
Pea gravel, with its smooth, rounded stones, offers excellent drainage and is relatively easy to work with. While not as stable as crushed stone due to its rounded shape, it can still provide a good sub-base, especially when combined with a layer of landscape fabric. It is often used in areas where drainage is a primary concern. It is less suitable for areas that will experience heavy foot traffic because it can shift under pressure.
Gravel Installation Tips
Installing a gravel sub-base is a straightforward process. First, excavate the area where the edging will be placed to a depth of several inches, depending on the size and type of edging you are using. A general rule is to excavate deep enough to accommodate a 2-4 inch layer of gravel. Next, compact the soil at the bottom of the excavation. Add the gravel in layers, compacting each layer thoroughly using a hand tamper or plate compactor. Ensure the gravel is level and provides a stable, even surface for the edging.
Sand: A Leveling and Cushioning Agent
Sand is another common material used under landscape edging, primarily for its leveling properties. It can easily fill in small gaps and irregularities, creating a smooth surface for the edging to rest upon.
Benefits of Using Sand
Sand’s fine particles allow for precise leveling, making it particularly useful when installing edging along uneven terrain. It also acts as a cushion, protecting the edging from direct contact with potentially sharp or abrasive soil particles. This cushioning effect can help prevent cracking or chipping, extending the lifespan of your edging.
Considerations for Sand Usage
While sand offers benefits, it also has limitations. Sand is prone to erosion, especially in areas with heavy rainfall or irrigation. It doesn’t provide the same level of stability as gravel and may not be suitable for heavy edging materials. It’s best used in conjunction with other materials, such as gravel, or in areas where drainage is less of a concern.
Sand Installation Best Practices
To use sand effectively, first, prepare the ground by excavating and compacting the soil. Then, add a layer of gravel for drainage and stability. On top of the gravel, spread a layer of sand, typically 1-2 inches thick. Use a level to ensure the sand is evenly distributed and provides a smooth surface for the edging. Lightly compact the sand before installing the edging.
Landscape Fabric: Weed Control and Soil Separation
Landscape fabric, also known as weed barrier fabric, is a permeable material designed to suppress weed growth and prevent soil mixing. While not a structural sub-base on its own, it plays a crucial role in maintaining the integrity of your edging and reducing maintenance.
Why Use Landscape Fabric?
Landscape fabric blocks sunlight, preventing weed seeds from germinating in the soil beneath the edging. It also separates the sub-base material from the underlying soil, preventing them from mixing over time. This separation helps maintain the drainage properties of the sub-base and prevents soil erosion.
Types of Landscape Fabric
Landscape fabric comes in various thicknesses and materials. Woven fabric is more durable and resistant to tearing, making it suitable for areas with heavy foot traffic or rocky soil. Spun-bonded fabric is lighter and more affordable, ideal for general weed control in less demanding areas.
How to Install Landscape Fabric
Install landscape fabric after preparing the soil and adding the sub-base material (such as gravel or sand). Overlap the edges of the fabric by several inches to prevent weeds from growing through the seams. Secure the fabric with landscape staples to prevent it from shifting or blowing away. Cut holes in the fabric where you plan to plant flowers or shrubs.
Compacted Soil: A Basic Foundation (With Caveats)
In some cases, simply compacting the existing soil can serve as a basic sub-base for landscape edging, particularly for lightweight edging materials or in areas with well-draining soil. However, this approach has limitations and requires careful consideration.
When Compacted Soil Might Suffice
Compacted soil can be a viable option if your soil is naturally well-draining and stable, and you are using lightweight edging materials such as plastic or thin metal. It can also work if you are on a very tight budget and are willing to accept a shorter lifespan for your edging.
The Downsides of Relying on Compacted Soil
Compacted soil alone is susceptible to erosion, shifting, and weed growth. It doesn’t provide the same level of support and stability as gravel or other sub-base materials, which can lead to uneven edging and increased maintenance. Heavy rainfall or freeze-thaw cycles can quickly degrade a compacted soil sub-base.
Proper Compaction Techniques
If you choose to use compacted soil, proper preparation is essential. Remove any rocks, debris, and weeds from the area. Moisten the soil slightly (but not excessively) and compact it thoroughly using a hand tamper or plate compactor. Ensure the soil is level and provides a firm, even surface for the edging. Consider adding a layer of landscape fabric on top of the compacted soil for weed control.
Matching Sub-Base to Edging Material: Key Considerations
The type of edging material you choose will significantly influence the best sub-base option. Let’s examine some common edging materials and their ideal sub-bases.
Plastic Edging
Plastic edging is a budget-friendly option that is easy to install. For plastic edging, a combination of compacted soil and a thin layer of sand can be sufficient. The sand provides a smooth, level surface for the edging to rest upon. Landscape fabric underneath the sand will help prevent weed growth. Because plastic edging is lightweight, it doesn’t require a heavy-duty sub-base.
Metal Edging
Metal edging offers a clean, modern look and is more durable than plastic. A gravel sub-base is recommended for metal edging to provide stability and prevent shifting. Crushed stone is an excellent choice, as it provides a firm foundation and resists movement. Landscape fabric underneath the gravel will help prevent weed growth and soil mixing.
Stone or Brick Edging
Stone or brick edging is a classic choice that adds a touch of elegance to any landscape. Due to their weight, stone and brick edging require a robust sub-base. A thick layer of crushed stone is essential for providing a stable foundation. The crushed stone should be compacted thoroughly to prevent settling. Sand can be used on top of the crushed stone to create a level surface for laying the stones or bricks.
Wood Edging
Wood edging offers a natural, rustic look. However, wood is susceptible to rot and decay, so proper drainage is crucial. A gravel sub-base will help prevent water from accumulating around the wood and prolong its lifespan. Pea gravel is a good choice, as it allows for excellent drainage. Landscape fabric underneath the gravel will help prevent weed growth and soil contact, further protecting the wood.
Installation Tips for a Long-Lasting Edge
Beyond choosing the right material, meticulous installation is paramount for maximizing the lifespan and performance of your landscape edging. Here are some essential tips:
- Proper Excavation: Excavate deep enough to accommodate the edging material and the sub-base, plus a little extra. This ensures the edging sits flush with the surrounding ground and provides adequate support.
- Compaction is Key: Thoroughly compact each layer of the sub-base using a hand tamper or plate compactor. Compaction creates a stable foundation that resists settling and shifting.
- Leveling is Essential: Use a level to ensure the sub-base is even and provides a consistent surface for the edging. Uneven edging looks unsightly and can create tripping hazards.
- Secure the Edging: Follow the manufacturer’s instructions for securing the edging in place. This may involve using stakes, spikes, or other fasteners.
- Backfilling: After installing the edging, backfill around it with soil or mulch. This provides additional support and helps blend the edging into the landscape.
- Consider Drainage: If your area is prone to heavy rainfall or poor drainage, consider installing a drainage system, such as a French drain, behind the edging.
- Use landscape adhesive: Using a landscape adhesive when installing heavier brick, stone, or concrete edging can add significant stability to your edging project. This is particularly important when installing these materials on a slope.
Long-Term Maintenance for Edging Success
Once your landscape edging is installed, a little ongoing maintenance will keep it looking its best for years to come. Regularly inspect the edging for signs of damage, such as cracks, chips, or shifting. Repair any damage promptly to prevent it from worsening. Remove weeds that grow along the edges of the edging to prevent them from undermining the sub-base. Periodically replenish the mulch or gravel around the edging to maintain a consistent appearance and suppress weed growth. Finally, adjust the edging as needed to compensate for settling or shifting. A little preventative maintenance can save you significant time and money in the long run.
What is the primary purpose of putting something under landscape edging?
The main reason to put a material under landscape edging is to prevent weeds and grass from growing underneath it and invading your garden beds or lawn. A barrier helps to block sunlight and physically obstruct weed seeds from germinating in the soil directly below the edging. This reduces the need for frequent weeding and keeps your landscape looking clean and well-maintained.
Furthermore, a base layer can improve the stability and longevity of your landscape edging. It creates a firm, even surface that helps the edging stay in place, prevents it from sinking into the soil over time, and provides proper support, especially in areas prone to erosion or soil movement. This ensures the edging remains functional and aesthetically pleasing for years to come.
What are some common materials used as underlayment for landscape edging?
Several materials work well as underlayment for landscape edging, each with its own advantages. Landscape fabric is a popular choice because it is permeable, allowing water and nutrients to reach the soil while effectively blocking weeds. Gravel, such as pea gravel or crushed stone, is another good option, providing excellent drainage and weed suppression, plus it can add an attractive element to the edging.
Sand is a more affordable option that can help level the ground and prevent weed growth. However, it may not be as effective as landscape fabric or gravel in the long run and can sometimes wash away with heavy rain. Other options include cardboard or newspaper for eco-conscious gardeners, although these will decompose over time and may require occasional replacement.
How do I prepare the ground before installing underlayment for landscape edging?
Proper ground preparation is crucial for the effectiveness of the underlayment and the longevity of your landscape edging. Start by clearing the area where the edging will be installed. Remove any existing grass, weeds, rocks, and debris. Use a shovel or trowel to dig a shallow trench along the planned edging line, ensuring it is deep enough to accommodate both the edging and the underlayment material.
Once the area is cleared, level the soil as much as possible. This will help the edging sit evenly and prevent gaps underneath where weeds could grow. Use a rake or leveler to smooth out any bumps or uneven areas. Compact the soil lightly with a hand tamper or roller to create a stable base for the underlayment.
How much underlayment material should I use?
The amount of underlayment material you need depends on the specific material you are using and the type of soil you have. For landscape fabric, a single layer is usually sufficient. Ensure the fabric extends at least a few inches beyond the edging on both sides to provide ample coverage and prevent weeds from growing along the edges.
For gravel or sand, aim for a layer that is approximately 2-4 inches thick. This provides adequate weed suppression and good drainage. Adjust the thickness based on the soil’s composition; if the soil is particularly prone to weed growth or poor drainage, a slightly thicker layer may be necessary. Always ensure the underlayment is evenly distributed to maintain a consistent barrier.
Can I skip using underlayment for landscape edging?
While it’s possible to install landscape edging without underlayment, doing so can lead to several potential problems. Without a barrier, weeds and grass can easily grow underneath the edging and into your garden beds or lawn, requiring more frequent weeding and maintenance. This can be particularly problematic in areas with aggressive weed growth or poorly draining soil.
Additionally, skipping underlayment can reduce the stability and longevity of the edging itself. Without a firm, even base, the edging may sink into the soil over time or become dislodged, especially in areas prone to erosion. This can compromise the aesthetics of your landscape and require costly repairs or replacement in the future.
Does the type of landscape edging affect the choice of underlayment?
Yes, the type of landscape edging you choose can influence the best underlayment option. For flexible edging made of plastic or rubber, landscape fabric or sand are excellent choices because they provide a smooth, consistent surface. This allows the edging to bend and curve easily without being hindered by unevenness.
For more rigid edging materials like stone or metal, gravel or crushed stone might be more suitable. These materials provide a sturdier base that can support the weight of the edging and prevent it from shifting. Additionally, the texture of gravel can complement the aesthetic of natural stone edging. Consider the material and shape of your edging when selecting an appropriate underlayment.
How do I maintain the underlayment after installation?
Maintaining the underlayment after installation is important for ensuring its continued effectiveness. Periodically inspect the edging and the surrounding area for any signs of weed growth. If weeds do appear, remove them promptly by hand or with a weeding tool to prevent them from spreading.
For underlayments like gravel or sand, occasionally replenish the material as needed to maintain the desired thickness. Over time, these materials can settle or erode, reducing their effectiveness. For landscape fabric, check for any tears or damage and repair them promptly to prevent weed growth. Regularly maintaining the underlayment will prolong its lifespan and keep your landscape looking its best.