Raised garden beds have increased in popularity in both residential and commercial spaces. Unfortunately, there are so many different potential options when it comes to building raised beds that aspiring gardeners get confused.
So, if you’re wondering if decking can be good for raised beds, the answer is yes! Believe it or not, many people actually use decking boards during the construction of their raised beds.
Different Types of Decking for Raised Beds
Since there are various forms of decking materials that can be used, it goes without saying that the same is true when using decking to build your raised beds.
Let’s take a look at three of the most popular types of decking used for raised beds, allowing you to determine which option best suits your needs.
Cedar Decking for Raised Beds
Cedar has been used for years to make garden beds.
Cedar is a high-quality wood with rot-resistance properties and the ability to withstand the elements. This wood is available in many different species and is the most popular option for patio decking.
There’s a good reason why cedar is used so often for raised beds.
For garden enthusiasts, the appearance of the garden is just as important as the plants. When a garden looks good, it just makes you feel good. Since wood is natural, it adds a bit of charm to the natural beauty of the plants.
Cedar contains certain chemicals that make the wood rot-resistant. Keep in mind that you should purchase cedar with no sapwood present, as this will cause the boards to rot.
When compared to some material options, cedar is relatively lightweight. This is important because its lightweight makes it easier to transport and assemble.
When cedar reaches the end of its lifespan, it can be left in its place to “melt” into the soil. If there are any usable pieces of the wood left, they can be used for other projects and purposes, including trellises and stakes.
Like any type of material, cedar has its disadvantages as well.
When cedar is left untreated, it can fade to silverish-grey.
Depending on the amount of sunlight in your area, this fading process can take two to three years, sometimes more. It is possible to preserve the cedar colour by using an exterior finish on the wood.
If you plan on adding a finish, it is recommended to do so prior to assembling the garden beds and planting your crops.
Due to so many different variables that come into play, it is hard to determine just how long a cedar-raised garden bed will last. In dryer areas, it will last for some time, but it may not last long in rainy areas.
There are wood treatments that can increase the lifespan of the wood if desired. So, when compared to options like recycled plastic beds, cedar beds have a shorter lifespan overall.
Recycled Plastic (HDPE) Decking for Raised Beds
High-density polyethylene plastic is a popular form of recycled plastic that’s used in the construction of raised beds. This plastic is durable and has been used for years to create picnic tables, boardwalks, and raised beds.
HDPE has seen a lot more use in recent years, and for good reason.
Recycled plastic raised beds are often guaranteed to last for life. In fact, manufacturers generally say that these types of beds can last a minimum of 50 years.
HDPE holds up exceptionally well to wear and tear. It does not sustain damage easily, as it is resistant to cracking, chipping, and other forms of damage even during extreme temperature fluctuations.
HDPE is a very stable material. It doesn’t leach toxic or non-toxic chemicals into the soil. You also don’t have to worry about the recycled plastic decking boards twisting, warping, shrinking, expanding, or contracting.
Unlike wood, recycled plastic will not fade, even after being exposed to the elements for decades. If the boards are scratched, you can hardly see it. However, a propane torch can be used to melt the scratch so it is completely unseen.
In the event that you need to dispose of your recycled plastic raised bed, the material remains 100% recyclable. In fact, some facilities may pay you for HDPE plastic, as it can be melted and reused.
Despite its growing popularity, there are some drawbacks to this material as well.
Lack of Linear Strength
When compared to wood, recycled HDPE plastic will sag in the middle when picked up at one end.
For this reason, cross-bracing is necessary to keep them from bowing. Ideally, if the bed is six feet or longer, it should be braced with a flat, straight bar of aluminium.
Due to its durability and longevity, recycled HDPE is one of the highest-quality plastics. It also costs more to manufacture, which is reflected in the cost.
When compared to cedar beds, recycled plastic beds will cost more upfront. However, in the end, the long-term savings with recycled plastic is greater.
Composite Decking for Raised Beds
Composite decking boards are made of a combination of recycled HDPE and wood fibres. They tend to be an earthy brown hue with a wood grain texture. Flanged corner joints are used to stack the beds.
Here at Elevate Decking, we love to use composite decking, and it can also be used to build raised decks if you know what you’re doing.
Out of all three materials, composite decking boards are the lightest. There is a stiffener placed in the middle of the hollow board for strength. Due to their lighter weight, composite beds are easy to transport and assemble.
Ease of Assembly
As mentioned, the light weight of composite boards makes it easier to assemble and even disassemble. If you move to a new property, you can easily tear down your composite garden beds and take them with you.
Composite beds have a unique wood grain imprint, mimicking the appearance of real wood. Unlike natural wood, composite boards don’t have knots or variations in colour/texture.
Composite materials can easily be kept clean with a quick hose down from the garden hose.
A short, light spray will remove anything that has built up on the surface. You can scrub off any heavier accumulation. To ensure you don’t scratch the finish, make sure to avoid abrasive sponges and cleaners.
It’s important to know the drawbacks of composite decking as well.
Unlike cedar and recycled plastic, composite materials can sustain scratches, cracks, etc. when struck by a heavy tool. Therefore, take care when transporting the boards, weed eating around the bed, etc.
The taller and longer you build your bed with composite boards, the more pressure is placed on the sides of the boards. This increased weight can lead to them bowing out.
While composite decking comes with a protective UV coating, colour fading may occur in areas exposed to the sun for extended periods. However, the protective coating will help maintain the boards for many years.
While all three options of decking materials are excellent choices for building a garden bed, cedar beds tend to beat out the other two. Of course, you will need to take into account your personal preferences, climate, budget, etc. before deciding which option would be best for your garden beds.
For a traditional or rustic appearance, cedar is ideal. For a garden centre or commercial garden, recycled beds are ideal since they can take some abuse here and there and can hold up to heavier use. For those who are looking to create a unique bed, composite boards are ideal.