he Herb Spiral is a highly productive and energy efficient, vertical garden design. It allows you to stack plants to maximise space - a practical and attractive solution for urban gardeners. It is typically 1.5 – 2m (5 – 6.5ft) wide in diameter at the base, ascending to 1.0 – 1.3m (3.2 – 4.2ft), with the centre of the spiral at the highest point. The spiral ramp provides a planting area large enough to accommodate all your common culinary herbs.