Southern Africa is known for its scorching temperatures and dry spells that can last for what seems months. Combine that with thin layers of soil and you can begin to see a problem when it comes to growing produce. To combat this harsh climate, humanitarian aid groups have developed various sustainable gardening techniques that allow families and villages to grow food throughout the year. One such technique is what’s become known as keyhole gardening.
So what is keyhole gardening? In its simplest form, a keyhole garden is essentially a raised-bed planter with several important modifications. These modifications include its circular shape, a composting bin at the center, as well as the integration of recyclable material, like cardboard and newspaper.
The benefits of the keyhole garden design are plentiful. The inclusion of cardboard and newspaper increase levels of carbon, nitrogen, and air to the soil. The composting bin helps keep soil moist and continually provides nutrients to the plants. Waste is being reduced by recycling organic food scraps and paper products that might otherwise end up in the trash. And remember, keyhole gardens were designed with hot, dry climates in mind. This means they retain water better, which reduces the need for frequent watering.
Keyhole gardens can be created by following these steps:
- Build a circular wall using bricks, stones, wood, etc. The optimal diameter is approximately six feet and the wall should be about three feet in height.
- Use a wire mesh material to create a tube that will act as the compost bin. The tube should be about one foot in diameter and four feet in height. Place the tube at the center of the circle.
- Remove a small section of the outer wall and rearrange the material to form two walls that run to the compost bin at the center. Picture a pie with one slice removed.
- Line the walls and bottom layer of the garden with cardboard, newspaper, and other compostable material. Add additional layers of leaves, small twigs, grass clippings, and other organic matter. Wet the layers as you place them. The top (planting) layer should consist of good potting soil and compost. The soil should slope down from the compost bin at the center toward the outer wall.
- Fill the compost bin with organic food scraps and other material that you would normally compost. Things like raw vegetable scraps and peelings, coffee grounds, egg shells, banana peels, apple cores, grass clippings, etc. For more ideas, take a look at this list of 81 things that can go into a compost bin.
- Poles extending upwards around the garden can be added to hold a shade cloth, if necessary.
- After a month or two, the soil level will drop some due to the bottom layers of the garden decomposing, so you may need to add additional soil to the top layer after this happens.
- Plant your fruits and vegetables.
For more ideas on building and planting your own keyhole garden, take a look at our Keyhole Gardening board on Pinterest. If you’d like to speak to one of our qualified landscape designers, gives us a call at 317-867-4811 or simply fill out the form below.