Abridged from The Basic of Permaculture Design by Ross Mars.
Nature is full of patterns and shapes. You can find intricate spirals in sunflowers and galaxies, hexagons in bee hives and circles in rain drops and winds. Mathematical shapes like squares, prisms and rectangles are rare in nature. They may occur in some chemical crystal formations, but spirals and circles are much more common in the Universe.
Patterns are found in every known ecosystem, and the interface or boundary between two ecosystems is extremely rich in life – in complexity, abundance and variety. The interface between different surfaces, objects or ecosystems is known as the edge. It is where the air meets the water, the forest meets the grassland, the land meets the ocean, as well as the area above and below the frost line on a hillside and the zone around a plant root in the soil.
The edge is rich in life because it contains species typical of each side, such as those in a forest or grassland, and species unique to the boundary itself. Edges are very productive systems as there is more light available in these areas, a large variety of plants are found there, animals seek protection, food and shelter and make their homes there and the resources of two ecosystems are shared.
This is why permaculturists create designs with large amounts of edge and particular patterns; hence circles, keyholes and curved garden beds.
Changing the shape of garden beds not only increases the amount of edge, and therefore production, it saves on watering. For example, circle garden beds are far easier and more economical to water with a sprinkler or spray system than a rectangular or square bed, as most sprinklers project a circular spray of water.
Figure 1 Changing the shape changes the amount of surface area or edge.
Convoluted garden beds as shown in the diagram below have a greater surface area or edge than the rectangular beds. More plants can be grown in these types of ‘folded’ garden beds. Common types of garden beds used in permaculture designs include:
(a) herb spiral. This garden bed is built like a pyramid, with a path or water line spiralling upwards. The circular base of the herb spiral is usually about two metres diameter and rises about one metre above the ground, but it can be larger and higher, or smaller than this.
A spiral is a useful pattern as the amount of edge and growing space increases as the garden bed climbs higher.
(b) circle. These are very common beds and they are usually between one to one and a half metres diameter. If you make them too wide you cannot easily reach all plants, so these beds are deliberately small.
Some people make each circle garden bed a different theme. For example, planting tomatoes, basil and other Mediterranean herbs and vegetables as an Italian cooking theme, or having a circle bed for medicinal herbs, cooking herbs, teas and drinks (lemon grass, lemon verbena and lemon balm and so on) or pest repellent herbs. Herbs are good companions for vegetables.
Figure 2 A herb spiral.
Figure 3 Circle garden beds are very common.
(c) keyhole. The “keyhole” can either be the path that you step into to reach your bed or the shape of the garden bed itself.
Keyhole paths allow easy-reach access to all plants.
(d) clipping and plucking beds. These types of beds contain vegetables that you can snip things from – maybe a leaf or flower – as you would for lettuce and nasturtiums. You can walk alongside plucking beds and harvest foods such as tomatoes, silverbeet, spinach, parsley, capsicums and many other useful foods. See Figure 5 which depicts a narrow plucking bed.
(e) narrow beds. Mainly designed and built for narrow garden places where you don’t have much room, but what you have can be effectively used to grow vegetables such as onions and chives.
(f) broad beds. Many summer crops such as melons and pumpkin require room to spread. Once the initial mounds are seeded and the vine crops start to grow, allow them to fill the area, as this helps reduce weed infestation.
(g) vertical. Small-sized gardens may have to utilise vertical growing space. Think about using fences or trellis for vines (grape, pumpkin, cucumber, squash), berries (soft fruit, such as boysenberries and raspberries) and peas and beans. Trellises can be used to provide shade and create suntraps. Trellises range from wooden lattice structures to wire strung up between poles to allow a vine or creeper to grow up and into a tree.
(h) raised garden beds. Not everyone is able to bend over gardening all the time – and who wants to anyway? Building a garden bed off the ground is a simple solution. You can build gardens on top of old, single, wire bed frames or box a garden with sleepers or concrete slabs. People in wheelchairs will be able to access and enjoy their gardens, and young children find it easier to work on these types of garden beds.
Figure 4 Keyholes allow easy access to all parts of the garden bed.
Figure 5 Narrow beds are ideal in small spaces. You can harvest from a plucking bed as you walk along the path.
Figure 6 Broad beds are good for melons and vine crops.
There is no limit to the diversity of plant and animal species that can be integrated in the terrestrial polyculture system, and the layout of the plants can vary also. For example, instead of planting in rows, with particular spacing, trees can be clumped one to one and a half metres apart, leaving available ground for interplanting.
Figure 7 Use vertical growing space for greater food production.
Figure 8 Espalier and fan pruning are techniques to utilise vertical and horizontal growth in fruit trees.
Figure 9 Raised garden beds can be built on any ground surface.
Figure 10 Underplant orchard trees with herbs and ground covers.
Sometimes, orchard trees can be clumped, but generally fruit trees should be at least three metres apart. Planting pioneer leguminous trees, such as Acacia and Albizia spp., amongst the edible food crops and fruit trees further enhances the system. Underplanting your fruit trees with pest repellent herbs and other good companions makes these trees healthy and reduces the need for other types of pest control.