At Deep Roots Project, we carefully research best practices using a wide range of trusted sources before making gardening recommendations. Our goal is to teach a method that makes food gardening not only successful, but also as easy and low-maintenance as possible—especially for busy people who want great results with less work.
Raised bed soil should touch the native soil below.
If you're installing a raised bed on gravel, place the gravel around the bed, not directly under the bed. Also, using landscape fabric under raised beds creates more risks and hassles than benefits.
Placing raised garden beds directly on compacted gravel or cement can significantly impede plant health and productivity. If you want gravel around your raised beds for convenience or aesthetics make sure you leave an area without gravel directly below the bed frame.
Drainage challenges and root development: Compacted gravel lacks the porosity necessary for proper water drainage. This can result in water pooling at the base of the raised bed, leading to waterlogged soil conditions. Such conditions deprive plant roots of essential oxygen, potentially causing root rot and stunted growth. Moreover, the hard surface of compacted gravel can act as a barrier, preventing roots from extending into the native soil below, thereby limiting access to deeper nutrients and moisture reserves.
Disruption of soil ecosystem: A thriving garden relies on a dynamic soil ecosystem, rich with microorganisms, fungi, earthworms and beneficial insects. These organisms play a crucial role in nutrient cycling and soil structure maintenance. When a raised bed is isolated from the native soil by a compacted gravel layer, it restricts the movement of these organisms into the bed. This isolation can lead to a less active soil ecosystem, reducing the natural fertility and resilience of the garden bed.
Landscape fabric under raised beds
causes more harm than good
Soil leakage and weeds: Most gardeners worry that soil will leak into the gravel or that weeds will creep up from below. But research and experience show that weeds rarely grow up through 15 inches of compost. Instead, they arrive from windblown seeds landing on the surface. And gravel itself is a natural weed deterrent. So putting plastic fabric between your gravel and raised bed won’t stop weeds—it just creates more work later.
Drainage issues: Landscape fabric also traps moisture and can interfere with drainage. If it gets clogged or pressed against uneven gravel, water may build up instead of draining freely, leading to soggy roots. Worse, it blocks the natural exchange of air, microbes, and moisture between the soil and the earth below. Over time, that hurts soil health and the thriving underground ecosystem your plants depend on.
Microplastic and chemical contamination: Another downside? Landscape fabric eventually breaks down into microplastics. Polypropylene, the most common material in these fabrics, doesn’t biodegrade. As it ages, it sheds plastic fibers into the soil—polluting your garden for years to come. Some fabrics also leach chemical into the soil over time.
In short, landscape fabric and gravel under raised beds may seem like a good idea, but it causes more harm than good. Stick with natural solutions, and you’ll support healthy soil, clean pathways, and a garden that grows stronger every year.
Ways to contain soil leakage onto gravel
So what can you do if you’re worried about raised bed soil (compost) leaking into your decorative gravel surrounding your bed? There are smart, ways to contain soil:
Add coarse gravel pebbles: The best solution with the least work is to spread coarse gravel pebbles over your fine gravel extending about a foot around the bed. If soil leaks out of the bottom it will mix with the fine gravel and be hidden by the course gravel. Best choice is gray pebbles (also called pea gravel) with same gray color as your fine gravel.
Recess the bed slightly—dig a shallow trench (2–3 inches) into the gravel so the bed frame sits lower. This helps hold in compost at the base.
Line the bottom inside edge with cedar boards, bricks. These act as a gentle barrier without sealing off water flow.
Add a natural breathable liner like burlap or straw inside the base of the bed. These will decompose safely over time while filtering fine soil particles during the first rains.
Ensure optimal garden health
A bonus tip: when you use 100% compost as you new “soil,” as Deep Roots Project recommends, it holds together better than blended soils. Compost's rich microbial structure helps it settle firmly and resist leaking.
By ensuring raised beds have direct contact with the native soil and are free from obstructive layers, gardeners can promote a healthier, more productive growing environment. Recommendations for optimal garden health to ensure the success of raised beds:
• Establish direct soil contact: Position raised beds so they rest directly on native soil, facilitating root expansion and organism movement.
• Enhance soil structure: Incorporate organic matter, such as compost, to improve soil aeration and water retention.
Avoid physical barriers: Refrain from using landscape fabric or similar materials beneath the bed, as they can hinder drainage and organism migration.
Join the Deep Roots movement
We’re not just about gardening; we’re about changing the way people grow food. Whether you have a tiny balcony or a full backyard, we’ll help you grow like a pro.
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Get involved: Attend a free workshop, become a volunteer, grab a raised bed, or simply follow along for expert tips. Contact our support team any time you have a question at 708-655-5299 and support@deep-roots-project.org.
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Dive Deeper
Click on the Blog Posts Below for more about our Innovative methods.
Beautify Your Garden with Our Cedar Raised Beds!
Our Deep Roots handcrafted cedar raised beds are designed to endure outdoors while adding a touch of style to your yard. As a bonus, they are the perfect depth to hold just the right amount of our nutrient-rich compost growing medium, which comes free with each bed.
Deep Roots Supports Gardeners
We provide our gardeners with the best products for success – like cedar raised beds, microbe-rich compost and microbe-rich worm castings. Check our online store. Always talk to our customer support team before placing your order online. If you need help or have a question contact us at support[at]deep-roots-project.org and 708-655-5299.
Deep Roots Online Store
See our online store for details about prices, ordering and delivery of raised beds, planter boxes, microbe-rich compost, worm castings, leaf mulch and more. We don’t sell traditional soil, since we use 100% compost as our growing medium. Our online store has 2 sections – (1) raised beds and planter boxes and (2) compost, worm castings, fertilizer.
Please contact our customer support team before placing an order online so we can assist you with the details and answer your gardening questions. You can pay by credit card in the store or by check.
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