What to Put Under Rocks for Landscaping: Discover the Best Materials for a Beautiful Rock Landscape

When incorporating rocks into landscaping, it's important to consider not just their visual appeal but also the underlying layer that determines their performance and longevity. Generally, what's placed beneath landscaping rocks can include options like landscape fabric, plastic sheeting, gravel, or even sand. Each material serves specific purposes:

1. Landscape Fabric: This is the most popular choice. It allows water and air to flow while suppressing weeds, keeping your rock beds low-maintenance and attractive for years.
2. Gravel or Crushed Stone Base: Placing a layer of fine gravel or crushed granite under larger decorative rocks ensures superior drainage, especially for high-traffic areas or slopes. This prevents rock shifting and mitigates soil erosion.
3. Sand: Occasionally, a sand layer is used to level out uneven terrain before installing either fabric or gravel, but it's generally not enough on its own for weed prevention.
4. Plastic Sheeting: Though sometimes used as a weed barrier, it's less favored by professionals as it can trap moisture, leading to poor soil health and potential water pooling issues.

Choosing the right underlayment is crucial: it improves longevity, reduces weeds, enhances drainage, and maintains tidy rock boundaries. As a designer, I always recommend starting with a carefully selected base tailored to your climate and plant needs. Not only does this foundation support the rocks' aesthetic, but it also contributes to a cohesive and sustainable landscape design. If you want to visualize how different sublayers affect the finished look and feel, tools like an AI Interior Design platform can let you experiment virtually before you begin—helping you design with both beauty and practicality in mind.

Tips 1:

Always secure your landscape fabric with garden staples to prevent shifting beneath the rocks. Overlap fabric edges by at least 6 inches to block persistent weeds. Make sure to slope the bed slightly away from structures for adequate drainage, and choose rock sizes that harmonize with plantings and hardscapes for a balanced visual effect.

FAQ

Q: Can I put rocks directly on soil for landscaping?

A: It's not recommended, as this can lead to weed growth, soil erosion, and shifting rocks. Always use a proper base layer.

Q: How thick should the layer under the rocks be?

A: Landscape fabric should cover the entire area, while gravel layers typically range from 2–4 inches deep for stability and drainage.

Q: Will landscape fabric eventually break down?

A: Quality landscape fabric can last for several years but will eventually degrade, especially with UV exposure or heavy foot traffic.

Q: Is plastic sheeting a good alternative to landscape fabric?

A: Plastic sheeting is less breathable and can cause water pooling, so landscape fabric is preferred for healthier soil and plants.

Q: Should I use sand under landscaping rocks?

A: Sand can help with leveling but is rarely used as the sole underlayer, as it doesn't prevent weeds or offer much stability compared to fabric or gravel.