Keyhole Garden. A keyhole garden introduces a no-dig, permaculture design in the form of a raised bed with a continual feed at the top for manure, vegetable scraps, paper and other brown and green matter. A keyhole garden is a round garden bed with a compost pile in the center.
The garden uses a number of layers to retain moisture and nourish the soil, making it more productive than a conventional garden. No hunching, no kneeling, no kneeboards - just you, standing comfortably to plant, water, weed, and harvest. Properly maintained keyhole gardens are very moist and nutrient-dense.
Keyhole gardens were part of a vast humanitarian effort.
Keyhole gardening is simple enough to be taught to school-age children in third-world countries where the children then use the concept in their homes and villages.
The idea of a keyhole garden. The design - which looks like a keyhole from above - incorporates a central 'basket' where compostable waste is placed and greywater is poured. A keyhole garden is a remarkably adaptable element that works in a range of garden styles.