Keyhole Garden: The African Method to Grow Your Own Food

If you live in a hot, arid climate, growing a vegetable garden can be impossible.

It can be hard to find the space and resources that you need to create a sustainable garden. But you can combine readily available supplies to create a keyhole garden of your own.

Does that sound too good to be true? Read along to learn all about these resilient raised garden beds.

What is a Keyhole Garden?

A keyhole garden is a small circular raised bed with an indentation on one side. The keyhole-like indentation isn’t there for aesthetic purposes. It’s used as an access point for food waste, gray water, and manure.

These compounds are used to fortify the compost bin located in the center of the garden. With a constant source of revitalizing nutrients and plenty of moisture, keyhole gardens have the potential to yield bountiful crops.

Keyhole gardens originated in Lesotho, Africa. They made it possible for homeowners to grow gardens in otherwise unsavory conditions. The idea can be credited to CARE (Cooperative for Assistance and Relief Everywhere).

Keyhole gardens were part of a vast humanitarian effort. They were intended to empower individuals to feed themselves. Since keyhole gardens utilize easily acquired materials, they are affordable and easy to make.

Properly maintained keyhole gardens are very moist and nutrient-dense. They can host dense plant vegetable and herb arrangements. Because of their impressive yields, keyhole gardens have gained popularity with gardeners around the world.

Why Should You Plant a Keyhole Garden?

Affordable

Keyhole gardens are made from bricks, concrete blocks, rocks, and other inexpensive stackable materials. There’s no need to purchase pricey or new materials. Just use the supplies you have on hand or repurpose discarded building materials.

Sustainable

Keyhole gardens are a type of permaculture. There’s no need to add store-bought nutrients or fertilizers. Just add old food scraps or manure to feed the compost pile in the center of the garden.

Low-Maintenance

Keyhole gardens are designed to stay moist when little precipitation is available. While you will need to make amendments to your keyhole garden compost pile, this is far easier and less expensive than adding commercial fertilizers.

As the compost decomposes, it releases rich, beneficial nutrients into the soil. This enables gardeners to feed their plants while reducing their waste.

High Yields

Keyhole gardens enable growers to stack plants unusually close to one another. You could fit as many as 70 tomato plants in a single 6-foot diameter keyhole garden.

Optimize Space

A traditional keyhole garden is just a few feet in diameter but it can house dozens of plants.

Keyhole gardens provide unlikely abundances to growers with small yards, community garden plots, or rooftop gardens.

Where to Put a Keyhole Garden?

Don’t stress about the placement of your keyhole garden. Just be sure that there is sufficient space for 6 1/2 feet of garden.

These African container gardens have their own built-in drainage system and they are raised off the ground. So the pre-existing soil conditions have no impact on the plants.

Place your garden in a flat, sunny spot. You want the ground to be level and have good drainage.

Keyhole gardens are popular in hot, dry environments, as these places are otherwise unfavorable for growing.

Space your garden apart from tall trees and plants. Extensive root systems have the potential to starve your garden of essential nutrients.

What to Plant in a Keyhole Garden?

There is a wide range of plants that are suitable for a keyhole garden. We’ve organized these into leafy crops and root crops. We’ve also included a rundown of plants that are not ideal for keyhole gardens.

Leafy Crops

Most growers prefer to plant a variety of leafy and root crops.

According to the Baker Institute, the following leafy plants do great in keyhole gardens:

• Lettuce
• Swiss Chard
• Spinach
• Rape
• Mustard Spinach
• Herbs

Root Crops

The following root crops also do well in keyhole gardens:

• Carrot
• Onion
• Beetroot
• Radish
• Turnips
• Garlic

Unsuitable Crops

The structure of keyhole gardens makes them poor environments for wide-spreading plants, such as:

• Tomatoes
• Peppers
• Cabbages
• Eggplants
• Corn
• Beans
• Squash

How to Make a Keyhole Garden

Start the Foundation

First, identify a suitable space for the keyhole garden. Keep in mind that keyhole a keyhole garden should measure 2 meters or 6 1/2 feet in diameter. Clear the area of plants, rocks, and roots. Stake out the perimeter and the center.

Place your posts in a square-shape arrangement in the center of the plot. Use a rubber mallet to pound the stakes into the earth. Later, these stakes will be used to support the compost cage.

Build the Base

Gather free, readily available materials to create the keyhole garden walls. Stones, cement blocks, and used tires are just a few examples of commonly used building materials.

Place the building material around the perimeter of the circle you created. Create a notch-like indent on one side of the circle. The walls should extend to the wooden posts in the center, offering easy access to the future compost cage.

Encircle the Compost Cage

Use mesh wire, sticks, or string to create a dense layer around the wooden posts. You want to create a basket-like container that can hold composting materials and water.

The container should allow moisture and nutrients to leech into the nearby soil. It should be taller than the top layer of your wall. Most compost cages are about 4 feet tall and 1 foot in diameter.

Once you establish your compost cage, you may wish to rearrange the outer wall of your keyhole garden to offer better access. Experienced gardeners typically split the sides of foundation so that they provide a clear path to the compost cage.

Build Up the Wall

Now stack the outer perimeter of your keyhole garden until it is about 3 feet high. It doesn’t matter which materials you use. Mix and match if you need to. The wall needs to be strong enough to contain soil and plants. It needs to be able to withstand adverse weather.

You may also wish to add to the foundation of your wall as your plants grow. This method requires you to stack materials so that they extend just beyond the base of plants.

Create the Bottom Layer of Your Garden

Create a thick yet biodegradable floor for your garden. Use old newspapers, yard clippings, broken clay pots, and aluminum cans to line the floor and walls. Using these materials, create a slope that extends from the compost cage to the garden walls.

Add Potting Soil

After that, you’ll need to add a thick layer of potting soil and manure. The soil mixture should slope down from the composting cage to maximize drainage and nutrient dispersion.

Plant Your Seeds

Select plants that match up to our approved plant list in the section above. Place root crops next to leafy crops. This will help preserve the plants while keeping pests away.

Always plant a variety of plants to optimize the outcome of your harvests. Consider planting a “salad garden” to ensure that well-paired plants are ready to eat at the same time.

Water the Fixings

Water your garden heavily when your plants are young. This will help the plants to develop healthy root systems.

Winterize the Garden

Keyhole gardens offer the potential for year-round gardening. However, not all climates support winter growth.

If you live in an area that experiences extreme winters, consider winterizing your keyhole garden. Cover the soil in a biodegradable material or rug to protect your garden from damaging frosts.

Tips for Planting a Keyhole Garden

There are a few things you can do to improve the outlook of your keyhole garden.

Size Matters

Keyhole gardens are designed for small spaces. Make sure that your garden is no more than 6 feet in diameter. This will optimize the distribution of nutrients from the internal compost cage.

Focus on the Foundation

Make sure that the foundation of your keyhole garden is solid. You want the soil to be compact to ensure proper drainage and moisture retention.

Create a Closed System

Don’t forget to add a garden floor. This essential layer helps trap in moisture and nutrients. Without it, essential plant foods will leech into the soil beneath your keyhole garden.

Keep in mind that you need a lot of material to make the base. Most garden experts recommend creating a 6-inch base. Save yard clippings, newspapers, and paper bags to ensure you have enough material to fill your garden.

Prioritize Food Waste

Make a habit of adding food scraps to the compost cage in the center of your keyhole garden. If your family makes a lot of food waste, make your cage extra large.

If you live in an area with lots of wilderness, you may need to reinforce or cover your compost cage. Think about this when selecting materials to wrap around the wooden garden stakes.

Add Layers

Build your garden in layers, rather than working from the outside in. You can always start with a low foundation and add height as your garden grows.

Focus on adding a floor, a growing base, and an outer perimeter. Make sure to slop the sides of the floor and soil to ensure optimal aeration.

Add Earthworms

Worms speed up the composting process. Purchase some red wrigglers and add them to the bottom of your compost cage. Vermicompost systems create nutrient-dense compost.

Use Dry Manure

Manure is a great source of carbon. It also helps aerate the soil to prevent runoff. Be careful not to add overly moist manure, as it can kill your seedlings.

Mix Up Your Plants

We cannot stress the importance of planting a wide variety of vegetables. Try to plant both leafy greens and root crops.

Commit yourself to plant at least four different types of plants. This way, if one plant succumbs to a pest, the others still have a chance.

Throw in Some Green and Brown

Break up your compost pile with layers of brown and green biodegradable materials. Coffee grinds, fresh grass clippings, and paper bags are just a few solid options.

Replace Your Soil Every Few Years

You can use your keyhole garden year after year. However, it is a good idea to add new soil to avoid depleting the system of quintessential nutrients.

Use Plants as Pesticides

Did you know that onions and garlic can be used to fend off pests? The strong odor of these plants serves as an organic deterrent.

These delectable root plants are also welcome additions to any keyhole garden.

Use Soapy Water

Spray soapy water on your plants to fend off the pest. Just be sure to wash your plants before eating them!

Apply Gray Water

If you’re deadset on planting a keyhole garden, it’s probably because you live in an arid climate. If this is the case, you will need to water your garden frequently.

Try using gray water, or clean wastewater, to save money and reduce your environmental impact.

Final Thoughts

While keyhole gardens were designed to sustain struggling Africans, they’re now popular with gardens around the world.

These tiny gardens ingeniously combine a growing foundation and compost pile to create a self-sustaining system that can survive in adverse conditions.

Keyhole gardens let you grow dense plantings with high success rates. The best part is that these gardens can be built by anyone anywhere!

All you need is a 6-foot space to get started. Fill your keyhole garden with greens and roots plants and enjoy a neverending harvest of nutrient-dense delights.