What are the practical advantages of using a Keyhole Garden Structure? Well-fed soil - as the compost is watered, minerals and nutrients are leached out to feed the soil. This is a continual process; as the basket is topped up, the contents rot down! Ease of access for weeding - weeding can be kept to a minimum by mulching the soil surface. However, when it is necessary, the ‘keyhole’ allows good access to all parts of the garden. Good moisture retention - watering the garden via the compost basket means water reaches the deeper parts of the garden. The sloping soil and mulching helps to retain moisture and plants grown in the garden often survive dry periods better than ordinary beds. No loss of soil - the retaining ‘walls’ of the garden mean that soil is conserved and not easily eroded or washed away. High productivity - the gardens are extremely productive for the area of land used. This is due to the good soil depth, therefore allowing root development, compost feeding and good water retention.