There are many different raised garden bed designs that you can easily build yourself. Most of them use wood or plywood for the outer wall. The keyhole raised vegetable garden bed, is a little different. The outer wall is built using bricks and it has a section in the center that is used for watering and feeding your vegetable with nutrients from your compost. This design is very popular in Africa, however it can be built anywhere in the world. Why are people falling in love with this type of garden? Probably because it waters and fertilizes itself.
Here’s What You’ll Need:
- Wooden Posts
- Bamboo canes or sticks
- Top Soil
- Compost (cardboard, newspaper, leaves, manure, ash, charcoal)
- Pea Gravel (optional)
- Wire Mesh (optional)
The first thing you have to do is clear out a flat area about 3 meters in diameter. This is where you are going to build your garden. Then you mark out the circumference about a 1.2m radius. Dig up soil if compacted then start to build the outer wall, laying the first layer of bricks at a 40 degree angle. Mark your entrance, before building the next two layers of bricks. The entrance is the last section of the outer wall build.
The inner circle that acts as the watering/compost section has a diameter of 40cm. Some designs use wire mesh instead of bamboo canes to create the wall for this section. Fill up the whole structure inside the brick walls with soil. The keyhole garden is ready, plant your vegetables and then feed them with water and compost, via the structure in the middle. Watch the African version video below, to see how they water and layer the compost.
Here’s another design by the Valhalla Project, they show you how to set up the compost for the keyhole raised garden bed.