Mandala Garden

A mandala garden is a kitchen garden arranged in a circle: the ground is cut into wedges like slices of a pie, with curved paths between them and something at the centre - a small pond, a spiral of herbs, a standing tree. The point of the shape is that every part of every bed is reachable from a path, so nobody stands on growing soil, and the whole plot stays within a few paces of one centre - which is what gets a garden visited often enough to stay on top of it. Soil that is walked on packs down, holding less air and water and making it harder for roots to push through, so confining the treading to narrow lanes protects the rest.

Beds are sized by how far a person can reach rather than by the pattern: about 1.2 m (4 ft) across for an adult and 0.9 m (3 ft) for a child, less again where a wheelchair is used. Paths want 45 to 60 cm (18 to 24 in). Six hours of direct sun a day is the floor and eight to ten the working figure - and it bites harder here than on a rectangular plot, because the wedges face every direction at once and anything tall at the centre shades some of them part of every day. Each wedge works as a separate unit, which makes it easy to keep one plant family to a bed and not bring it back for about three years.

That rotation breaks the life cycles of pests that specialise in one family. It is also what gets forgotten, since the wedges look alike, so the plan has to be written down. The classic pairing is a movable poultry pen worked from wedge to wedge, with one real warning: raw bird droppings can make people ill, and the interval is 120 days between spreading and harvesting anything that touches the soil, 90 days for the rest. Ageing a heap is not composting it. A wedge also widens towards its rim, so the outer end is soon too wide to reach across and gets trodden anyway. Straight-sided things - row covers, hoops, cold frames, drip lines - fit nothing here, so each is cut for one bed and will not move to the next.