Building a Raised Garden Into a Hillside.




Introduction: Building a Raised Garden Into a Hillside.

About: I'm a Special Education Teacher with 7 kids. I use donated and salvaged tech to teach STEM with my students and kids. Someday I'll get all of my projects posted up. For now, it's nonstop DIY, teaching and doin…

I have a small backyard with very little level ground and plenty of shade.  I wanted to expand my garden, but the prime real-estate was up a six foot incline to my back fence.  It took a lot of digging and what seemed like endless root cutting from a former maple tree to tame this hillside.  I ended up with: four 4x8 beds, one 8x8 bed, four 2x4 beds and some additional areas for shade plants at the top.


Per 4x8 bed

1  4x4x8'
6   4x3/4''x8' (pressure treated fence boards)
1  cu yds of generic garden soil
1/2 bag sphagnum peat moss
2 bags compost manure
2 bags quality garden soil (miracle grow, etc.)

Step 1: Building the Frames

I decided to make the first beds using mortise and tenon joints because I liked the look.  It looks similar to a bed frame when assembled.  I used my router with a guide attached and a 3/4'' spiral cut bit.  This made the 3/4'' side fit tightly in the mortises.  I made several passes, gradually plunging deeper each time to achieve the desired depth of the mortise to prevent overheating the bit.  

Dry fit everything to make sure you haven't made any mistakes before digging your footings.  Because these beds are set into a hillside, it is best to anchor your 4x4 posts in the ground.

Tip:Make a Story Stick to mark the position of every cut and mortise.  Use your Story Stick to mark each board, rather than your tape measure.  This makes marking your wood much faster and will ensure uniform cuts on each piece.  

Step 2: Filling With Soil.

Once your beds are in place and you are happy with your alignment, you can begin filling them with soil.  It is also recommended that you add a layer of mesh wire to the bottom to prevent unwanted guest from digging up into your beds.  It will take about 1.25 cu yds of soil to fill a typical 4x8x1 bed.  I ordered 5 cu yds of garden soil from a local nursery to start my beds off.  I then added a layer of sphagnum peat moss, 2 bags of compost manure and 2 bags of quality vegetable garden soil to each 4x8 bed.  I worked everything into the soil before planting.  

I used left over stones from our patio to build the steps.  They ended up looking pretty good and it didn't cost me anything!  

Step 3: Planting

I began most of my garden from seeds.  I then transplanted everything to other beds.  It is critical to follow the advice for spacing.  Some plants like squash get very large and will shade out plants that are too close.  After your first season, you will get the hang of this.  But in general, pay attention to how the sunlight tracks across your yard for the entire day.  Plant taller plants, like tomatoes and corn in the back to prevent them from shading shorter plants like strawberries and peppers.

Some plants grow well together.  A Three Sisters Garden has corn, beans and squash.  The beans use the corn stalks as support and the squash shades out weeds.

Keep your garden watered, but not over watered.  I attached two brass sprinklers to metal stakes and put them on an inexpensive digital timer.  Everything gets watered about 1/2'' every two days this way.  

Step 4: This Year's Addition Complete.

Now it's time to sit back, relax and enjoy your bounty.  Yeh right, you better get started pulling those weeds now!

In hind sight, I don't know that mortise and tenon joints were the best choice because they could cause the wood to rot a little more quickly.  Time will tell.... but they look great!

Step 5: Harvest Time

I decided to add some pics here as I harvest during the summer.

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    7 years ago on Introduction


    Thanks for the walkthrough. We have a small backyard as well.. looks to be at least twice as steep as yours. Right now it's just sitting there so i think it's time to put it to use.

    Might you be able to share a list of tools you used for this project? I'm just starting out and it's time to increase my garage arsenal.



    9 years ago on Step 2

    is that a chilipepper plant i see there?
    Anyway, beautiful set up

    Nice one bizy dad! One thing I've started to do in my garden is to place a piece of treated 2x4 screwed into the posts/side of the beds with the top at the same level as the grass. Then when you mow the grass the mower goes on top of the 4" wood and cuts ALL the grass, no trimming the long stuff that grows up the side of the beds with a strimmer afterwards.

    You would have to notch yours around the posts but it should still work ok.

    I am slowly eradicating all the areas in my garden that need the pesky strimmer, so that I can just mow, mow, mow!


    Reply 9 years ago on Introduction

    That's a great idea! I am going to have to pick up some 2x4's and try that. My battery powered weed eater died over the winter and I found out that a new battery cost more than I paid for the trimmer (with a battery). Rebuilding that battery might be a future project I'll have to look into. Thanks!


    9 years ago

    Pressure treated pine and other woods are no good for food products. Bad idea. Cedar would be a much better choice


    Reply 9 years ago on Introduction

    Cedar is nice and probably a nicer looking alternative. I did some research before building the beds to check on the concern of using pressure treated wood in vegetable gardens. It used to be not recommended because of the copper and arsenic used in the wood. However, they stopped using those chemicals several years ago (2006 I think) and the wood is no longer considered a concern. I forgot to mention in my Instructable that I lined the beds and the walls up to just under the soil level, just as an extra precaution. It was probably unnecessary, but made me feel better. If you do use older pressure treated wood, it is still considered safe according to more recent scientific studies. Studies have shown that the arsenic levels leached into the soil are no more than you would already find in nature. Even then, the leaching mainly occurs during the first rainy season and only into the soil a few inches from the wood. In addition, organic soil helps to prevent arsenic from actually being absorbed by plants. The copper is still a concern, so lining beds made with pressure treated lumber and keeping plants away from the edges can still be a good idea. Thanks for pointing that out.


    9 years ago on Introduction

    I can see that you put a lot of effort in the care of your garden. Great work! There is a trend to cultivate edibles on homeowners yards. Anyone can tell the difference of a tomato harvested at home compared to one bought at the supermarket. It tastes much better!