I added raised beds to my backyard garden ten years ago and I wish I had added them sooner. Growing from raised beds has benefits that all can enjoy right away. For instance, raised beds in the garden help to decrease weed count in your growing area. Using raised beds aids soil management in a determined area. Raised beds make it easier for persons to work their garden plants and soil without having to get all the way down to ground level. Additionally, raised beds support growth organization and can be aesthetically pleasing. These are just a few of the general benefits of using raised beds for planting almost anything. In the reminder of this article, I will elaborate on the details of constructing various raised beds for gardening, as well as the benefits of growing out of raised beds. I’ll also touch on some aspects of raised bed gardening that I tried and then modified through the years.
Initial Construction of my Raised Beds:
The construction of the raised beds for the garden was relatively straight forward. I purchased two untreated wood boards to create the sides of my raised beds. Steer clear of treated lumber. Building raised beds from treated lumber is frowned upon due to the chemicals employed in the treatment of the lumber. Although treated lumber will last longer outside, the chemicals the lumber is infused with will eventually leach into the raised bed soil and contaminate the soil and possibly the plants as well. As far as the best type of untreated wood to use for the raised bed construction, Cedar is recommended. Cedar is naturally rot resistant and so it will hold up under the elements a bit longer than other types of untreated lumber. If you are willing to pay more for cedar, it will last longer before rotting out. I have to admit, I’ve used pieces of untreated lumber that I had lying around in my barn because it was cheaper. Cedar is recommended, but my first raised beds were built on a budget. The untreated lumber that I used still lasted several growing seasons before I had to begin replacing boards. Plus, repurposing scrap wood is a great way to recycle while saving a few dollars. Plus, have you seen the price of wood lately?
Initial Mistakes I Made Building the Raised Beds:
An initial mistake I made is that I decided to screw boards directly together. I inserted two decking screws directly through the shorter width board into the longer length boards of the rectangular box. Very basic construction, but not very good construction. This is not the ideal way to screw the rectangular box sides together. Eventually over time, the wood will rot out and the screws will potentially find their way into your soil mixture, or stick out of the boards and act as a hazard to your hands, and feet, and ankles. This became a bit of a nuisance to me while gardening and also looked quite shoddy (see image to the right). So I decided to remove and replace the rotted pieces of wood and stabilize them into the rectangular box by pounding 1×1 wooden pegs into the ground along the outside perimeter. I wanted to see if I could keep the raised bed box together without using screws (seen in the next picture). I also experimented with other ways to use screws when constructing the raised beds, and I’ll show and review those later in this article too.
The wooden pegs that I placed around the outside perimeter held the boards up and into place fairly well. I used a hand held auger to drill a hole into the ground next to the side board of the raised bed, then inserted the one by ones into the ground to support the raised bed side board. But I must admit that this system was not perfect and did eventually weaken, allowing some of the dirt from the raised bed to escape at the corners (see pegs in the picture 1a to the right).
I also tried another method of utilizing deck screws and then screwing the side panels into a one-by-one at each corner (see picture 1b). I do think this way is a better method versus just screwing the side boards together. Screwing the side panels into the one-by-ones at the corner is a better design, and has been more stable over a longer time period. All I did was cut one-by-ones to the same length as the side board height of my raised bed box. Next, I used decking wood screws to screw through the side board into the one-by-one. Two screws for each side. For instance, I used a total of 16 screws to build the box in picture 1b. Eight around the top corners, and eight around the bottom corners. Just keep in mind that when you do this, you need to stagger the positioning of the decking screws so the two screws coming in from one side of the box into the one-by-one do not interfere with the two screws that come in to the same one-by-one from the opposite side.
Benefits of Using Raised Beds (in no particular order):
It is easier to keep the soil weed free. The raised bed is a great way to create a barrier between your finely tuned soil and the weeds that may be trying to invade. Year over year, it is much easier to maintain the soil in the raised bed area because weed and pest infiltration is greatly decreased due to the raised bed barriers. For added protection, you can add a weed cloth barrier at the bottom of your raised bed area being sure to allow the barrier material to come up the side of your raised box an inch or two prior to filling your raised bed with soil.
It is easier to maintain soil composition. I often use a mixture of organic soils and homemade compost in my raised bed areas. The raised bed area is great for soil management because it is easier to not only know more precisely what you are putting into that specific raised bed area, but loss of soil is greatly diminished over time due to the raised bed barriers. My garden is situated on a gradual slope, so the raised beds help to reduce possibly run-off while helping to support leveling and terracing.
My veggies grow better in the raised bed space. Carrots in particular grow much better in the raised bed area. Prior to planting in my raised bed space, my carrot growth was a little more dysmorphic and a little less predictable. Since the quality of soil in the raised bed area is easier to maintain and fine tune, I was able to provide soil for my carrots that allowed for a more efficient growth path. The result was fantastic!
It is easier to work the garden in a raised bed. If you have difficulty getting on the ground to tend to your plants or soil, a raised bed area can definitely make this task easier. Since you can make the raised bed just about any level, you can build the bed to a height that is most suitable for you to work around.
Raised beds can be aesthetically pleasing. If organizing makes you smile, then seeing the order of multiple raised beds in your garden will bring a smile to your face. So in addition to providing you with fresh organic fruits and veggies, the organized nature of the raised bed garden can also promote positive physical and emotional health. Having various raised bed spaces in my garden lets me think about my garden layout throughout the offseason. This helps me feel more organized when it is time to get down to planting. If you are like me, the spring planting season is very busy for a multitude of reasons and having my thoughts organized regarding my raised garden boxes is a proactive bonus!
Water management and soil temperature can be beneficial aspects of raised bed use. Since I constantly add my own composted soil to my raised bed soil, the composition of the soil is far better than that of the ground soil in other parts of my garden. This also helps support better water retention and water drainage which ultimately leads to a better vegetable yield. Also as a side benefit, I sometimes begin to grow and produce sooner in my raised beds because the soil temperature warms up sooner at the beginning of the growing season. The temperature aspect is not significantly different, but is noticeable in that I even see volunteers pop up sooner in the raised bed areas versus the ground garden areas.
Types of Raised Beds One Can Create:
Raised Soil Bed – This raised soil bed is the easiest to create because there are few resources needed. This is quite literally an area in the garden that is built up with compost and soil, mounded at a level higher than the ground level (approximately 3-6 inches), and sectioned off by digging out the perimeter to define the space. This is the first type of raised bed that I had in the garden and it was easy-breezy. Most of the work went into creating the organic compost used to mix into the soil in the rectangular area that I had dug out. Digging out the perimeter with a shovel helps to prevent weed infiltration and basically protects and defines the raised soil bed as wood boards might in a raised garden box. A couple times a year, I add additional soil from my compost pile. Once or twice in the spring, I till the soil. One can till the soil with a garden rake or shovel, or one can use a motorized tiller as I do. This is one of the benefits of the raised soil garden bed, in that it is easier to till with a motorized tiller. Which ever method you use, be sure to till and turn the soil over at a depth of 6-8 inches. One draw back to the raised soil bed in my garden is soil loss. My garden is placed on a piece of land that gradually slopes. It can be frustrating to see soil loss from runoff after a big rain storm. This is one of the reasons I built raised wooden beds in my garden. Plus, my wife wanted them! Overall though, the raised soil bed works well and I have used them for years, and still do to this day. They are basic, but more functional on a relatively flat piece of land. One last thing I do around my raised soil beds is keep a path of grass. Having grass around the perimeter of the raised soil beds helps to mitigate any soil runoff due to intense rains, and I like the way it looks.
Elevated Raised Bed Boxes or Containers – Elevated raised bed gardening is very popular, especially in spots where outside ground space is at a minimum. Many box stores sell DIY kits for creating elevated raised garden beds, and others home gardeners have engineered ways to create these elevated beds using various bins, tubs, wood, or a combination of these materials. Of the three raised bed types that I discuss here, the elevated raised bed probably requires the most work to create and keep going. If you have experience container growing, then you know that when you are not directly connected to the soil and earth, plant growth and yield can be affected. I found this to be the case and thus focus most of my growing in raised beds that have a direct connection to the earth. Meaning, the organic soil and compost that I place into my raised bed is on top of the earths soil. But that being said, the elevated raised bed gardening technique is the best for those growing in an area where there may be no ground soil access. One of the great benefits of the elevated raised bed is that it can be placed directly on top of a concrete pad or outside deck and act as a functional gardening space. There are benefits to elevated raised bed gardening too. For instance, since the raised bed is elevated off of the ground, the weed barrier is awesome. Pests have greater difficulty infiltrating the soil as well. Most of the ground dwelling plant eaters will have a difficult time getting to these plants and since you can elevate the area based on your height, growing in an elevated bed can be easier to access as well. Although, getting the soil into the elevated bed can be tough on the back too! Lastly, growing from the elevated raised bed, possibly right on the back patio, makes for easy access given the usual close proximity of an elevated raised bed. Since many elevated raised bed boxes come in kit form, some big box stores will even put them together for you, for a nominal fee.
Raised Bed Box in the Garden – This type is the raised bed type I use most often. I prefer it over the raised soil bed because it allows me to mix and build better soil while preventing soil loss due to rain runoff. Creating the box is not overly difficult, yet I have gone through several methods of creating the raised box as stated earlier in this article. This season, the newest raised bed that I created is one that does not require any screw placement at all. I purchased my untreated side boards from one of the big box stores. If you know your measurements, they will cut the wood to your measurements at the store for free. Regarding the size or perimeter of your rectangular raised garden bed, it is a personal choice based on a couple of factors. The size of your raised bed will depend on the size of the space you have available, as well as the items you plan on planting in the box. Most of my raised beds are 6 to 8 feet long, and the width of each varies depending on the garden space I have available. One modification I have made since designing my first raised beds is to make sure I do not make the width of the raised bed box greater than the distance I can reach. The width of my first raised garden box was too wide for me and I had difficulty managing all of the plants in the bed. I was unable to easily reach plants growing towards the center of these raised beds, so keep your arm length in mind when determining the width of your raised bed. Regarding the height of the side boards that make up your raised beds, a popular height is approximately 10 inches or so. So this means that the height of your raised bed will be approximately 10 inches above the ground’s surface. Some of my raised bed boxes vary in height, often dependent on the wood that I have readily available at the time.
However, my most recent raised bed creation is created from just two materials. Untreated wood makes up the side board walls of the bed, and all of the boards are held in place by an engineered stone that holds the boards in place. The biggest drawback for me is that the material for this type of raised bed is a bit more expensive.
I like the idea of an interlocking raised bed system though because it is easier to put together, no screws and power tools necessary. As a result, when the wood starts to degrade, I can easily replace the boards without having to deal with screws that have degraded alongside of the degraded wood. When I put together my first interlocking raised bed, it was quick and relatively simple. The slight increase in material expense, is overshadowed by the ease of construction and ease of future board replacement. As a side benefit, it is easy to scale the raised bed higher because the engineered corner stones are stackable. Just make sure you start building on a level surface.
Bonus Way to Promote Raised Bed Growing Success:
One not-so-secret strategy I recently started using with my raised beds is to fill the bottom of the bed with found tree wood debris and parts. I live in a wooded area and split firewood throughout the year, so finding wood remnants is pretty easy. Basically, I first dig a trench and remove some of the soil down the middle of the raised bed area. Be sure to save the top soil to place back into the raised bed. I collect downed tree parts including hunks of degrading wood, limbs, and bark. I cut any larger wood part down to a foot or less and then spread them out at the bottom of the trench that I dug out. Bigger found wood tree limbs and parts can also be used, it is personal preference. I organize the tree parts into a crisscross pattern or perpendicular pattern.
I then place additional compost and other organic matter like decaying leaves or grass clippings on top of the wood pieces. Finally, I add the top soil back into the raised garden bed to top it all off. This is a modified Hugelkultur method. Some benefits of this method include saving on soil and organic compost. Given the time it takes to create my own compost, I use it wisely and only as needed. The modified Hugelkultur method helps me to use my premium compost wisely.
This method also provides a way to manage soil aeration and greatly supports water filtration and retention. Water retention can sometimes be a problem in raised bed areas and this method supports better water retention all season long. The decaying wood and organic matter creates a better environment for water retention, and also presents a great home for worms and the microorganisms that supplement soil composition. Also, the decaying wood and organic matter will ultimately release supplemental elements back into the soil which aids soil composition and plant growth all season long.