Keyhole Garden: The Phenomenal African Compost Garden

A keyhole garden is one of the most interesting types of gardens. Perhaps you need plants that don’t grow well in your area. Or maybe you want to live a self-sustainable lifestyle. Your reason could even be that you just need a distraction.  

Keyhole GardenView in gallery
Image from Wikipedia

One great type of garden you can use has been around for about thirty years now and it is phenomenal. It’s called a keyhole garden, and it may be just as magical as its name, especially if you have a fantastical imagination. 

What Is A Keyhole Garden?

A keyhole garden may sound like a cool, high-end type of garden but it’s actually a way to minimize waste and promote efficiency. Keyhole gardens were designed so that you could grow plants no matter where you lived.

They were first built in the 1990s in a small nation known as Lesotho in southern Africa. The area didn’t have the most fertile soil and discovered a way to get around this and still grow tasty veggies.

Why The Keyhole Garden? 

Keyhole raised bedsView in gallery
Image from Abundant Design, LLC

While the term keyhole garden is now used loosely, the original keyhole gardens were shaped like a keyhole, with a place to stand in the center to reach the entire garden. The term has changed only slightly since then.

The keyhole garden is made in a raised garden bed, usually in a circular pattern. A wedge is cut out to allow easy access to the entire garden. Primarily access to the center, where the compost bin is placed.

Yes, this is the key to making a keyhole garden. The compost cage is filled with yard and kitchen waste which contains great nutrients for the plants, working as fertilizer in otherwise not-so-fertile land.

How To Build A Keyhole Garden

Raised bed vegetable gardenView in gallery
Image from Land Design, Inc.

Building a keyhole garden will take some time but it isn’t as difficult as it may look. If you know how to build a raised garden bed then you already know how to take care of the most difficult part. Here’s the rest!

Step 1: Clear The Land

A keyhole garden doesn’t need a completely smooth surface, but you want the land to be as flat as possible to make building the retaining walls and working with drainage systems easier. So use an area with flat land.

Step 2: Create A Barrier

At least begin to make one. If you want a completely round keyhole garden then this is easy. But a stake in the center and attach a string to it. Then, attach a stake to the other end and make a circle in the dirt.

Mark the circle with a bed of rocks or something that will allow your place to be kept and won’t be moved by the wind. For non-round keyhole gardens, you can simply measure the area and mark it with boards. 

Step 3: Start The Cage

It’s a good idea for the compost cage to reach all the way down to the ground, so this is a good place to start. Make a compost bin out of chicken wire and secure it in the very center of your circle.

The cage should be about four feet tall and half as wide as the circle, if not a little less. The height should be one foot taller than what your wall will be. So if the wall is three feet, the cage should be four feet. 

Step 4: Build The Retaining Wall

The type of retaining wall that you build is completely up to you. We will go over choices later but it needs to be something strong that you like the look of. So after you mark the perimeter, you can build the wall in place. 

Before you finish building the wall, mark a notch out of the wall to become a keyhole. This is where you will stand to refill the compost bin so make it convenient. 

Step 5: Add A Drain

The best type of drain includes rocks, twigs, and similar materials that will allow water to pass through easily. This layer should be somewhere between 3 and 6 inches thick. If you plan on watering a lot, add another drain.

The other drain will be attached to the wall and will allow the water to be redirected to another area. You can use something like a French drain. This isn’t necessary because the ground will absorb the water in most cases. 

Step 6: The Bedded Layer

Add grass clippings, dried leaves, hay, and even paper to the next layer. This is the bed layer that goes just over the drain layer. It doesn’t need to be thick but it is a good insulator for the soil and drain layer.

Step 7: Add Soil

Now comes the thickest layer that should be at least 8-inches thick. This is where you add healthy soil to the mix. It is the top layer and will be when and where you plant your garden. It’s a good idea to add the mulch layer afterward. 

Step 8: Get To Work

Now it’s time to add your compost to the compost cage, plant your plants, and water the compost. Your plants should start growing soon and you can feel accomplished knowing you’re doing something good!

Utilizing Compost Correctly For A Keyhole Garden

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Image from here.

Composting is a method of fertilizing plants in the greenest way possible. You can use dried leaves, cut grass, and garbage to create compost that will feed your plants a balanced and healthy diet in your keyhole garden.

But there are a few things that you need to know if you are a beginner in the compost niche. This is all about installing your compost cage correctly and keeping your garden healthy. Replace the cage every three to four years. 

Center The Cage

The compost cage needs to be placed at the center so that it will continuously decompose and feed the entire garden. You can use chicken wire for the cage for a cheap and easy way to build it. Chicken wire can be bought at farm supply stores. 

Install A Good Drain

The reason that keyhole gardens are built up so high is that they need to drain properly. But even more than that, the compost needs water in order to decompose. So if you don’t let it drain, the water won’t do its job properly. 

Stake The Cage

This is optional but it can help with proper dispersal and keep it from collapsing when you add compost. You can stake it down into the soil and even place bars around it to keep it from tipping over.

Use Good Soil

Before long, you won’t need any soil at all as the compost will break down. But to begin with, you will need to buy a few bags of the best soil you can find. This will help your plants get a good start in the keyhole garden. 

Raise The Cage

It’s important that the cage is a couple of inches above the rest of the soil. This will ensure that the water runs down and around the entire garden. If it is level or lower than the rest of the area, it may not disperse the water and compost.

Don’t Forget Mulch

Dries leaves are a type of compost that you need to add to the top layer after you plant your plants. This will prevent the water in the soil from evaporating, which will help the compost decompose and activate. 

Keyhole Garden Framing

Stainless steel keyhole gardenView in gallery
Image from Blue Sky Agriscaping

There are only a few different types of retaining walls you can use for a keyhole garden. Although other options like concrete can work, it’s better not to use anything too permanent as you will want to replace it every few years. 

Stone Keyhole Garden

Stone is a good choice that looks amazing. You can build a stone retaining wall out of any medium-sized stone. Use a good adhesive that can be anything from clay to mortar. Just make sure it can be moved if need be. 

Brick Keyhole Garden

Brick is very similar to stone in the way that it is built. You can use brick for your retaining wall for your keyhole garden. It has a more modern look but it is cheaper and at times easier than using stone.

Wood Keyhole Garden

Wood is the most popular choice because it is easy to install. You can even buy keyhole garden kits or garden beds made from wood that are relatively inexpensive. It is also highly customizable, giving you a lot of options to work with.

Railroad Tie Keyhole Garden

This unique option isn’t a new one. In fact, it’s quite old. Back in the day, railroad ties were used because they were available. Now they are used because they are rare. Learn to build a railroad tie retaining wall to impress today. 

Choosing A Keyhole Garden

Since there are many other types of gardens out there, it can be difficult to decide if a keyhole garden is right for you. However, this is one of those cases where it doesn’t hurt to try it out, you can only learn from it.

So go ahead and build a keyhole garden if it is speaking to you. It’s always a good idea to do all of your research before deciding but if after a while, you still want to go with a keyhole garden, then give it a go!