Raised garden beds are excellent to grow vegetables in, however, finding inexpensive and toxin-free materials can be a real challenge. You’re probably thinking about using a raised bed liner to create a safe barrier, and you’re onto something there!
I’ve been experimenting with different raised bed materials for years and have finally landed on the perfect combination of durability + low cost + non-toxic materials.
In this article, I’ll share my easy and fairly inexpensive method for building a raised garden bed with a durable, non-toxic liner. All of these materials can be easily found at your local building supply store.
*Disclosure: This post may contain affiliate links to products (including Amazon). I’ll earn a small commission if you make a purchase through my link, at no additional cost to you! Regardless, I only link to products that I personally use on our homestead or believe in.
Raised garden beds are a popular gardening method that provides many benefits over traditional in-ground gardening. Raised beds allow for better drainage help prevent soil compaction reduce weeds, and make gardening more accessible. When building a raised bed, an important consideration is whether to line it, and if so, what material to use. The right liner can further maximize the advantages of raised bed gardening.
In this article, we will examine the top materials for lining raised garden beds and the key factors to consider when selecting one From natural fabric liners to durable plastic and permeable landscape fabric, we will cover the pros and cons of various liner options to help you make the best choice for your garden.
Why Use a Liner in a Raised Garden Bed?
There are several good reasons to use a liner in your raised bed
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Prevents weed growth – Liners act as a physical barrier to stop weed seeds in the soil below from sprouting up into your garden bed. This helps reduce unwanted weeds.
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Retains moisture – Some liner materials help conserve moisture and prevent water loss through drainage. This can reduce watering needs.
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Insulates soil – Liners moderate soil temperature fluctuations from extreme heat and cold. This protects plant roots.
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Deters pests – Impermeable liners can block pests like gophers from digging into beds from below.
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Contains soil – Liners prevent soil erosion and loss of nutrients from excessive drainage.
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Prevents contamination – Liners stop chemicals from treated wood or other materials from leaching into the soil.
Factors to Consider When Choosing a Raised Bed Liner
There are several variables to weigh when selecting a liner material:
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Climate and rainfall – In wet climates, you may need more permeability for drainage. In dry climates, you may want more moisture retention.
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Type of raised bed structure – If you use treated lumber, you need a barrier liner. For untreated wood beds, permeability is more important.
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Soil type – Sandy soils require more water retention, while clay soils need good drainage.
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Plant types – Root crops need unrestricted root growth. A liner may not be suitable.
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Pest pressures – Areas with gophers and moles benefit from subsurface barriers.
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Durability and maintenance – Frequency of replacing worn or damaged liners should be considered.
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Budget – Prices range from inexpensive cardboard to higher-cost rigid plastic liners.
Considering these factors will guide you in selecting the right liner materials for your unique raised bed gardening needs.
Top Materials for Raised Bed Liners
Now let’s dive into the specific materials that make good raised garden bed liners and the pros and cons of each option.
Landscape Fabric
Landscape fabric is a common choice for lining raised beds. The fabric is permeable to allow airflow and drainage while still suppressing weeds.
Pros:
- Allows drainage
- Discourages weeds
- Affordable pricing
- Easy installation
Cons:
- Less durable than plastic liners
- Not pest-proof
Overall, landscape fabric is a good choice for well-draining raised beds where weeds are the main concern. Just ensure adequate holes or gaps for drainage.
Plastic Liners
Plastic tarps and polypropylene fabric make effective waterproof liners. They excel at moisture retention.
Pros:
- Retains moisture well
- Long-lasting durability
- Easy to install
- Provides pest barrier
Cons:
- Impedes drainage without holes
- Can accumulate condensation
- Higher cost than fabrics
Plastic is a smart liner for drier climates or gardens with pest issues. Ensure proper drainage holes or gaps if soil tends to get waterlogged.
Burlap
As a natural fabric, burlap makes an eco-friendly raised bed liner that’s permeable and breathable.
Pros:
- Permeable for drainage
- Natural and biodegradable
- Low cost
Cons:
- Less durable than plastic
- Not pest-proof
- Can rot over time
For gardeners wanting a natural, non-toxic option, burlap is an affordable choice, despite a shorter lifespan. Ensure it is untreated.
Natural Burlap Garden Bed Liners
Burlap, made from jute fibers, is a biodegradable and natural option for garden bed liners. These chemical-free garden liners allow for good airflow and drainage while keeping weeds at bay. Over time, burlap naturally decomposes, enriching the soil instead of harming it. Since it’s free from synthetic chemicals, it provides a safe, organic solution for gardeners focused on non-toxic gardening practices.
Cardboard
Cardboard boxes or sheets can serve as an easy, biodegradable liner option. It suppresses weeds and retains some moisture.
Pros:
- Inexpensive and easily obtained
- Natural and compostable over time
- Allows some drainage
Cons:
- Short lifespan as material breaks down
- Not pest-proof
- Can fall apart when wet
For very short-term use, cardboard is a DIY option to line beds on a budget. Just replace frequently. Avoid treated cardboard.
Coconut Coir
Coconut coir mats provide an eco-friendly liner made from coconut husks. It retains moisture well while allowing drainage.
Pros:
- Sustainable and biodegradable
- Excellent moisture retention
- Permeable for drainage
- Longer-lasting than natural fabrics
Cons:
- Relatively high cost
- Somewhat less durable than plastic
- Not pest-proof
Coconut coir combines eco-friendly sustainability with moisture retention. It’s a premium natural option for raised bed liners.
Rubber
Rubber pond liners or BPA-free rubber provide a durable, non-toxic liner option. Rubber excels at moisture retention.
Pros:
- Superior moisture retention
- Long-lasting durability
- Non-toxic and chemical-free
Cons:
- Relatively expensive
- Needs drainage holes
- Heavier to install
For longevity and safety, rubber is a smart non-toxic liner choice despite the higher cost. Ensure adequate drainage.
Key Takeaways on Raised Bed Liner Materials
- Landscape fabric provides an affordable weed barrier but needs drainage gaps
- Plastic liners excel at moisture retention but require drainage holes
- Natural burlap is a cheap short-term option for non-toxic beds
- Coconut coir offers an eco-friendly medium-term moisture retention solution
- Rubber pond liners are durable, non-toxic, and moisture-retentive
- Ensure liner permeability matches your climate, soil, and plant needs
The ideal liner depends on your specific gardening requirements. Evaluate climate, soils, plant types, pests, costs, and durability when deciding on the best material. With the right liner, your raised bed will maximize production and enjoyment for years to come.
Landscape Fabric: 4
Plastic Liners: 5
Burlap: 5
Natural Burlap Garden Bed Liners: 1
Cardboard: 4
Coconut Coir: 4
Rubber: 4
Do I Need a Raised Bed Liner?
It depends on your raised bed design, but the short answer is yes. If you are using treated lumber, then you definitely do. There are many advantages to adding a liner along the inside edge of your garden bed.
If you are using a rot-resistant material like pressure-treated wood, then I highly recommend using a raised bed liner to keep the chemicals from leaching into the soil (and eventually your food). Pressure-treated wood is appealing to use because it’s inexpensive and will last up to 10 years, unlike most types of untreated wood.
Prior to 2003, arsenic was the chemical of choice for treated lumber. No thanks! Today, the most common chemical used is alkaline copper quat (ACQ). While this is a less toxic option than arsenic, it’s still not something that I want to mix with my food.
Common Raised Bed Liner Materials
There are several different materials out there that are commonly used as a raised bed liner. However, they all have their own shortfalls. Let’s break them down!
Most gardening books recommend using plastic to line your raised beds, however, I’m not a big fan. It doesn’t breathe well, so the moisture will cling to your raised bed materials causing them to break down faster. It’s a nightmare to work with and it’s hard to get it to lay neatly.
Plastic also breaks down quickly and won’t last much longer than 2 years. You’ll end up with plastic shards in your soil and have to dig out the soil to replace the plastic again. Lastly, who wants plastic surrounding their garden? I don’t.
Using landscaping fabric seems like a simple solution, however, the material is too thin to offer any benefits regarding stability or temperature moderation. Plus, landscaping fabric is a manufactured product that often contains chemicals and petroleum.
Lastly, while landscaping fabric is meant to be a physical barrier for weeds, it’s still permeable and I would worry about pressure-treated wood chemicals leaching through it. That would defeat the whole purpose of using it.
This is the least offensive option of the 3. It’s cheap, and would provide stability and temperature moderation. It’s a substantial enough barrier that it would likely prevent chemicals from leaching into the soil as well.
However, cardboard quickly decomposes and would need to be replaced year after year. I know I don’t have time for that!
Best Liner for Raised Garden Bed | Upgrade Your Gardening Skills
FAQ
What is the best material to line a raised garden bed?
You Can Use a Layer of Cardboard at the Bottom of Raised Beds to Prevent Weeds. If your budget doesn’t allow for weed barrier cloth, you can add several layers of cardboard to the bottom of your raised bed before filling it with soil. The cardboard will decompose in about 4 to 6 months.
What material is used for raised bed liners?
We’d thoroughly recommend you use one of our thick, one piece, polypropylene fabric raised bed liners when growing in raised beds on the patio; the porous material of the liner will help water retention, prevent the compost and soil from running out onto the hard surface – possibly causing staining – and will also help …
What should you put in the bottom of a raised garden bed?
All you have to do to hold the soil inside your raised bed is put down some type of porous material. You can do weed barrier cloth or plain ol’ burlap.Apr 27, 2024
What to line sleeper raised beds with?
Lining your raised bed with landscaping fabric, polythene or permeable membrane before adding in soil, is also a popular choice for increased durability.
What are raised bed liners?
Raised bed liners keep soil contained so you can install the beds on a patio, paved area or concrete slab — any hard surface — without soil washing out and making a mess. They help prevent weeds from infiltrating beds set in the lawn, too. Polypropylene fabric allows water to drain. Four sizes: 3′ x 3′, 3′ x 6′, 4′ x 4′ and 4′ x 8′.
Should you use a non-toxic garden bed liner?
Using a non-toxic garden bed liner is an essential step for any raised garden bed, especially when you want to protect both your plants and the environment. Certain materials used in raised bed structures, like treated wood or certain plastics, can leach harmful chemicals into the soil.
Are plastic liners good for raised garden beds?
Plastic liners are non-toxic and effective at weed control, making life easier for any beginner gardener. When choosing a liner for your raised garden bed, you want to ensure you’re getting the most bang for your buck—not just in cost but also in durability and longevity.
Do raised bed liners protect wood?
A raised bed liner to protect the wood helps prevent direct contact between the soil and the wood, significantly extending the life of your garden bed. Reports show that proper liners can reduce wood degradation by 30% or more. Raised garden bed liners help suppress weed growth by blocking weed seeds from penetrating the soil.
How do I choose a raised garden bed liner?
My top pick for a raised garden bed liner is a heavy-duty, breathable landscape fabric that allows for proper water drainage and aeration. One might think a thick plastic sheet could do the trick, but I’ve learned that this can hinder water and air flow, leading to over-saturated soil and unhappy plants.
What is a garden bed liner?
A garden bed liner is a barrier between the soil and whatever you choose to put in your garden bed – plants, mulch, rocks, or even concrete. It’s an important part of any garden because it helps keep the soil healthy and prevents unwanted pests, weeds, and other materials from entering the bed.