From a bird’s eye view the garden is shaped as a keyhole. A notch is cut into a round garden bed, the notch makes for easy access to the center compost well. They use kitchen and garden waste and gray water (or wash water) as food for your garden.
Large stones,bricks or logs
Straw or dry sticks
Several 5ft garden canes or similar
Broken plant pots or tin cans
A length of wire
Mixture of well-draining topsoil and compost plus some well-rotted animal manure
1. Dig over a space of 3 square metres. Tie a stick to each end of 1.2 metres of garden twine. Place one end in the centre of your space and use the other to mark a circle in the ground. Then draw out of an entrance triangle, from the circle to the centre starting at a width of 60cm.
3. Lay your stones,bricks or logs around the perimeter of your garden – this could be a single layer or more, but enough to keep the soil in. Build the stones higher at the entrance triangle. Make the first layer of the garden from broken plant pots or cans to improve drainage.
4. Now start filling the garden with the soil and compost. Make sure that the best soil goes on the top. Keep piling up the soil until you have a mound which slopes away from the basket.
5. Let the garden settle a week before planting your seeds and seedlings. To start with, water the soil surface until the roots grow, then water the basket with waste or rainwater, using the entrance. Add already composted material to the basket and continue to add compostable food-waste. A circle of carpet over the top of the basket will help speed up the composting process. The compost will permeate the garden and give your crops lots of nutrients.
Keyhole garden scheme. Layering is proven to enhance soil health.
There is a variety of designs as seeing below.
Keyhole garden with a surround of sticks.
Keyhole garden with wood surround.
Keyhole Vegetable Garden with straw wattle.
Watch this tutorial How to make a Keyhole Garden in Uganda by Send a Cow Organization.