Many gardening articles expound the advantages of a gentle southern sloping garden, but sometimes the slopes are a little too steep for effective gardening.
Or maybe the only space in your garden is a steep hillside, but the terraces are too expensive and labor-intensive. The solution: build a raised garden bed on the slope.

Gardening on slopes can lead to soil erosion as exposed soil and any accompanying nutrients are washed down the hillside.The key is to build a horizontal raised bed so you can stop erosion while reaping the benefits of raised beds and terraced gardens.

Building an elevated garden bed on a slope may seem like a daunting task that requires advanced carpentry skills, but it can be a very simple DIY project. Below we'll see how to accomplish it with minimal tools, mundane materials, and very basic building skills.

raised garden bed

Can you put a raised bed on the slope?

Absolute! In fact, building raised garden beds on slopes has many benefits, such as improved drainage, higher soil temperatures to plant earlier and extend the season, reduced erosion, and uniform distribution of water and nutrients. You just want to make sure that the finished box is horizontal and does not follow the contours of the ground.
When building a raised bed on flat ground, you simply build a box and put it down.
However, on slopes, simply placing the box on the ground will make the raised bed as bent as the ground. You want to lift one end so that your raised bed stays level when finished.

Do loft beds have to be horizontal?

No, they don't, but if they are, then it's better. If the raised bed is tilted, the plants at the top of the bed will dry out faster than the plants at the bottom. Alternatively, the plant at the bottom is at risk of being flooded. The plank at the bottom will also rot faster than the plank at the top, as water accumulates on the downward side. When the water washes to the bottom of the raised garden bed, it also washes away all the nutrients. During heavy rains, the soil itself can also be washed away directly from the elevated bed with freshly sown seeds.
Making sure your raised bed level will alleviate these issues.

The slope of the land

The first thing to do is to determine how inclined your land is. This is often described as "rising over run" or the distance the ground descends over a certain distance.
The higher the altitude, the steeper your mountain will be. Here's how to measure the slope of your land:

1. Place the carpenter's level on the ground.
2. Raise the downhill end of the high level until it is horizontal (the bubbles will be in the middle)
3. Most carpenter levels are 2 feet long, so in the middle of the level, measure from the bottom of the level to the ground (assuming this measurement is 4 inches)
4. Your land has a slope (ascent/run) of 4"/12", which means that for every foot you walk, the hill drops 4 inches.

Regardless of the slope, when building a raised bed on a hill, it is better to place the bed longitudinally along the slope than to slide it down the hill. The longer you go down the hill, the higher you have to raise the bed to make it flat, and the more wood you'll need.

raised garden bed

How big should my loft bed be?

On average, a raised bed should have a maximum width of 4 feet (1.2 meters) to facilitate weeding. They should be at least 6 inches (15 cm) deep, but 1 foot (30 cm) deep will hold most vegetables and plants. Raised beds can be as long as needed.
In this article, we will build a bulge that is 4 feet wide and 1 foot deep (on the uphill side, as it will be deeper on the downhill side) and 8 feet (2.4 meters) long.

How to build an raised garden bed on a slope

Now that you have everything planned, let's see how easily you can build a raised bed on the hill that won't break your bank or back.

1: Material
6 – 8 feet 2×6. Cut both ends in half.
Some extra 2x6 is used for vertical frame support and to fill any gaps.
3" Adox nails

2: Tools
Saws (hand saws or circular saws)
Safety gear or personal protective equipment such as gloves, goggles, etc.

3: Make a box.
The first step is to build the basic framework of the raised bed. Nail a 4ft 2x6 8ft 2x6 to the end of an 8ft 2x6 so you have a basic box. The box will be fragile, but that's okay now. Place the box where you want the raised bed.

4: Leveling the box.
Place your level on one of the 4-foot 2x6s and raise the downhill side of the box until small bubbles appear between the two lines.
But a block under the box can hold it in place. You can use rocks, wood, or other solid things as blocks.
Next, place the spirit level on one of the 8-foot 2x6s and raise one side of the box again as needed until the bubbles are centered.
Put the block here too. Check each side, make sure the box is level in each direction, and adjust as needed.

5: Put in the vertical bracket.
At each corner of the box, stand a 2×6 so that it touches the ground and extends at least 6 inches above the top of the box. Nail the box to these columns.
You also want to do this in the middle of 8 feet 2×6 to add support. If you build a bed that is longer than 8 feet, place another vertical support every 4 feet or so.
Tip: Instead of placing the brackets on the ground, cut them into a point and hammer them into the ground. This will add support to your raised bed, and you can skip step #6.

6: Fill in the gaps.
On the lower side of the box, there will be a gap between the bottom of the box and the ground. Connect an additional 2x6 to the vertical support until the space is covered.

Depending on the contours of your land, these gaps are usually funky shapes, so you may need to trim these planks slightly so that they fit, or you can dig out some dirt so that the planks fit and fit snugly against the ground.

If you end up with too little space to fit 2×6, you have a few options. First, see if you have a smaller board that fits, such as 2×4 or 2×2.

Or, if you're not worried about aesthetics (like most of my garden projects), just hammer 2×6 so that it overlaps the other boards. Finally, and more discerningly, the option is to cut 2×6 longitudinally at an angle so that it fits perfectly into the space.

(Be very careful when cutting boards longitudinally, as this can be very dangerous unless you have the proper tools and training). This is mostly a personal choice based on practicality rather than aesthetics.

If you still have some small gaps, don't worry because these can quickly clog over time. You can also clog them by placing a small stone on the inside of the garden bed to prevent soil from spilling.

6: Add top panel.
Now you can add the last layer of 2x6 by pinning them to a vertical support above the original box. This will provide you with a raised bed that is completed at a height of 1 foot on the uphill side and even higher on the downhill side.

7: Add a wooden stake to prevent the bed from sagging.
Over time, the weight of the soil in the raised bed puts pressure on both sides, especially the downhill side.

To keep your bed nice and square, you can put a stake on the side of the bed outside. You can use wood that slopes to a certain point, pieces of rebar or any other sturdy stake of your choice.

8: Fill and plant!
Your raised bed in the mountain garden is now complete and you can fill it with any growing medium you want.

raised garden bed

Building a raised bed on flat ground is one thing, but we can get discouraged when we look out at the hilly garden plot and try to plan our raised garden.
Even with basic construction skills, you can easily build elevated garden beds on slopes, I hope this article gives you the confidence to handle your project and create an efficient, beautiful, and one-of-a-kind raised bed garden.

December 25, 2022

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