July 2, 2012

The Permaculture Orchard

AT THE Permaculture Interpretive Garden—the PIG—we’re progressively establishing a forest garden that will eventually yield fruits, nuts, selected vegetables and herbs. It’s a long term project but we’ve made a good start.

It will be the outcome of a process that started with gaining Randwick City Council support for the project and engaging in a design process that included the adjacent community centre and more than a little permaculture design thinking. 

Permaculture is often defined as a system of design for sustainable human habitat. For the forest garden and the associated Randwick Community Centre development, permaculture is a design approach to sustainable urbanism that has informed the retrofitting of the community centre and the design of the PIG. It’s a long term vision that is steadily being realised and it’s the most recent landuse for an area that has seen

Location and history

Climatically, the Sydney region is favoured by a warm temperate climate with temperatures ranging  8 to 26°C and an average of 14 days a year when temperatures exceed 30°C with winter temperatures rarely falling below 5°C in coastal areas. The average annual rainfall, which can be quite variable, reaches 1217mm, however periods of drought occur during the El Nino phase of the Southern Oscillation and wetter than usual periods during the L Nina phase. 

The climate is appreciated by home and community gardeners and the region’s city fringe commercial market gardeners and orchardists because it allows the growing of crops from the cooler, temperate regions to the south as well as the subtropics to the north. It’s a botanically favoured climate. 

Only a few kilometres from the east coast where the waters of the Pacific lap at the beaches and cliffs of the Coogee shoreline, to the immediate south of the community centre and PIG is an open field of lawn used by local people for dog exercise and passive and active recreation beyond which are the southern Eastern Suburbs and Botany Bay; to the north stretch the Eastern Suburbs bordered by Sydney Harbour and the coast; to the immediate west a military base and beyond that the suburbs. 

Before European settlement the area was home to the Eora people for whom it provided their needs for at least 30,000 years.The site has long been used by the military and during World War Two was the storage area for the Allied navies in the Pacific. It was handed over to Randwick Council less than a decade ago.

Earlier in its ecological history the garden area was home to the shrubby Eastern Suburbs Banksia Scrub, a heathlike ecosystem of tough, close-packed bushland made up of small and large shrubs and low-growing trees. These evolved to draw nutrients from the often dry, low fertility sandy soils of the area through which rainwater and plant nutrients drain rapidly. 

You can visit this scrub in the reserve adjacent to the PIG. Here, it forms the vegetative cover for a low-lying area into which rainwater drains from the surrounding suburb and slowly infiltrates through the sandy soil into the underground water storage—the aquifer. It’s what we call and aquifer recharge zone and the banksia scrub and the filtering and slowing of that rainwater runoff and its seeping into the ground is what’s known as an environmental service, something valuable to the area’s ecology and to the people who draw water from the aquifer.

Prior to the design and development of the PIG, the area it occupies was covered by poor quality lawn and a few scattered and quite young tea trees (Malaleuca species). Public use was minimal and there was no use that the PIG does not now provide opportunity for. 

First things first—site & sector analysis

Design and development of the PIG formed an element within the retrofitting of the buildings of the adjacent Randwick Community Centre to demonstrate energy and water efficient design ideas and technologies. The Centre is a venue for public hire and for Randwick Council’s courses in sustainable gardening, forest gardening, community leadership, the early childhood teacher’s ecocentres course, the EcoHeroes children’s club and for the council’s school’s education program. Together, the community centre retrofit and the PIG make up the Randwick Sustainability Hub.

People from the local area as well as the community association, Permaculture Sydney East, participated in the redesign process for both the Centre and the PIG. The first step was to conduct a site and sector analysis to discover the characteristics of the site and the influences affecting it flowing in from the Eastern Suburbs region.

The site is approximately a hectare in area. 

Discovered during site and sector analysis for the PIG were:

  • unobstructed access to year-round sunlight; it can get quite hot and drying in summer necessitating regular irrigation of the vegetable and forest gardens
  • mild, cooling summer sea breezes from the north east to east
  • strong winds from seaward any time of year
  • cold, blustery and strong winter winds from the south to south west sector, a limiting feature of the site
  • low fertility, freely draining sandy soils
  • flat terrain with a gentle slope towards the south
  • an absence of boggy soils
  • an existing structure that commemorates the local history as a Navy stores base, consisting of a remnant concrete floor once part of a warehouse and a set of large, wooden doors supported by a steel framework
  • an absence of services such as underground sewage, water and gas, and of overhead cables
  • adjacent landuses consisting of a children’s playground, the community centre, a housing development and the remnant Eastern Suburbs Banksia Scrub; the Wildlife Information and Rescue Service maintains a cage inside the fence around the bushland reserve for the recovery of injured wildlife.

The permaculture design principle about seeing alternative solutions to problems was used regarding the strong winds affecting the site by installing an aerogenerator—a wind turbine—near the community centre to generate electricity to sell to the grid.

From needs identified by council’s sustainability educator, Fiona Campbell, and with the information gleaned from site and sector analysis, council’s consultant landscape architect and permaculture educator, Steve Batley of Sydney Organic Gardens, worked with Fiona to develop a design for what would become the PIG. 

The design

The design is unusual in urban planning in that it created a new type of public open space—a site that functions as an urban park and as an education facility for council. The permaculture principle employed in designing the PIG was that of multipurpose use, that the site should perform more than a single use.

A design criteria was to demonstrate take-home ideas that could be replicated in the home or community garden or that could be purchased and installed. 

Observation of how people use the site since it opened identifies:

  • the planned use as education facility
  • public use of the free gas barbecue and picnic tables
  • informal use as a playground for children on foot or bicycle who dart around the raised garden beds and look at the flowers and other plants
  • inspection tours by local government and other sustainability educators as well as community gardeners and urban agriculture specialists from the Sydney region, interstate and overseas.

The design can be thought of as dividing the site into several ‘rooms’ or specific use areas. These include:

  • a vegetable garden area 
  • a vertical garden to demonstrate the use of vertical surfaces for growing plants, including vegetables and herbs
  • a trellis demonstrating the growing of espaliered citrus trees as a fruit growing strategy for confined spaces
  • a container garden demonstration and education area for workshops in container gardens for the area’s apartment and townhouse dwellers
  • a compost education/workshop area consisting of a grassy lawn, compost bins and a couple almond trees that will eventually grow to shade the grass, making is suitable for summer picnics
  • a circle of large sandstone blocks paved with crushed, compacted granite below a pergola for socialising and for workshops; the pergola demonstrates the Fibonacci series, a mathematical pattern found in nature and forming a part of the PIG’s schools and permaculture education program 
  • a performance place making use of the structure commemorating the site’s naval stores history
  • an orchard or forest garden, often called a food forest
  • a garden of native plants for those interested in low maintenance, low-water use ornamental gardens
  • interpretive, educational signage explaining the PIG to visitors.

Linking the elements is a water movement and harvesting system that assists with irrigation.

The vegetable garden

Design criteria for the vegetable garden area reflected the multi-use purpose of the PIG. 

The vegetable garden is used to demonstrate and educate about home or community garden production of annual vegetables as well as culinary herbs. 

It’s big picture context is increasing urban food security and resilience, both of which figure in courses at the Sustainability Hub. Food security is an important consideration in Randwick as the suburb hosts a large number of social housing tenants who are among the low income demographic vulnerable to food insecurity due to rising food prices. 

The PIG’s educational function is accomplished during practical sessions of council’s sustainable gardening course, once a month PermaBee Dig Day's and, informally, via the interpretive signage in the garden. 

Another design criteria was to demonstrate take-home ideas for materials to use to build vegetable gardens and to demonstrate those that can be bought and installed. Demonstrated are different materials such as galvanised iron, stone, brick, recycled plastic planks (made from recycled mobile phone cases) and galvanised iron and hardwood. 

Some of the garden planters are scaled for children for use during council’s school education excursion program, another design criteria.

The rationale for demonstrating the galvanised iron planters that can be bought from garden supply shops recognises that many families and individuals are time poor and, even when they would like to build a home garden, they cannot allocate the time to it. Buying a planter or two of three, some composted material to fill it with, some seeds or seedlings, a little water and work can make an instant home garden in an afternoon. They’re also suitable for townhouse residents who have paved courtyards.

The forest garden

Why a forest garden?

Why make a forest garden? Whether you call it by that name or call it a food forest or orchard, here’s a few reasons to design and plant a forest garden:

  • forest gardens are scalable—they can be as large as as an urban backyard or as small as a few pots with  dwarf fruit trees on your apartment balcony
  • they are adaptable—the model can be applied in different climates with adjustments made or different, climatically-specific plant 
  • species and spacing of canopy and understorey plants
  • the model is suited to home gardens as well as community gardens and community orchards
  • forest gardens provide life resources—food, nesting, refuge—for wildlife such as the smaller birds in short supply in our cities and creatures like lizards and frogs; this is known as habitat
  • urban beautification and regreening, increasing the extent of the urban tree canopy
  • an educational resource for those who create and manage the forest garden as well as for those who visit it
  • forest gardens provide much the same environmental services as the natural forest—as well as wildlife habitat already mentioned, there’s the steady infiltration of rainfall into the soil as water drips rather than gushes erosively from the canopy, shade, humidity from evapotranspiration from foliage, windbreak and microclimate effects, soil stability through reduced soil erosion; soil production as fallen foliage and other organic material decomposes into humus, carbon sequestration and those things appreciated by humans—contact with nature and the seasons and a calming, beautiful place for people.

Design

What is a the forest garden? It’s is a conceptual model that blends fruit and nut trees and shrubs and vegetables that take up more space to grow such as Jerusalum artichoke, yakon (aka Peruvian ground apple—nothing to do with apples at all) or that are perennial, that grow for years, such as French sorrel, strawberries, rhubarb and New Zealand spinach. 

The design concept for the forest garden was based on a model of the natural forest occupying a number of vertical layers—ground covers and the immediate soil zone below, an intermediate layer of shrubs and small trees of different height and a top layer of tree canopy. Some natural forests have more layers than this, however the three level model is a manageable one for the food forest garden. There is also the root crop layer and the vertical layer - climbers.

The layers consist of a set of mutually supportive plants. There is the main crop—our fruit trees and shrubs—and planted adjacent to these are a support package of plants consisting of:

  • fertiliser plants—the legume shrubs, ground covers and climbers that incorporate the plant food nitrogen into the soil where it is accessed by plant roots
  • flowering plants—these attract pollinators like bees that fertilise our food plants; flowers also attract insects to feed from them and the predatory insects that in turn feed on them, including the pest insects that would infest our fruit and other crops; this established the basis of the insect food web that benefits our crops by keeping populations of pest insects in check, becoming part of an integrated pest management strategy for the forest garden; insects are also a food source for small birds which become part of that pest management strategy and which makes the forest garden a habitat for birds
  • mining plants—such as the ground level species, comfrey, whose deep roots bring to the surface deeper-lying nutrients where they are accessed by the roots of our food and support species
  • windbreak plants—those that protect our young citrus, pomegranate, olive and other slow-growing trees and shrubs from the strong, cold winds of winter that blow through the area; these will eventually form our tree canopy and yield fruit and nuts
  • fast fruits—because our main crop of fruit or nut trees and shrubs grows slowly, we can use the space between their seedlings as places to grow a temporary crop of fast growing fruits such as banana, tamarillo, pawpaw, blueberry and babaco; these will eventually be overshadowed and the space they are growing in taken over by our slower-growing main crop plants and they become bigger and as their canopies spread out; we will, however, keep areas where we can continue to cultivate the fast fruits.

This mutually-supportive package, this plant combination, is known as a plant guild and it forms one of the substructures, the planting pattern of our forest garden.

Soil improvement

This made improving soil fertility and structure a priority if we want to grow fruit and nuts as well as different types of vegetables, and is the reason that a succession of green manure crops have been cultivated. A green manure as already explained is a combination of two plant types—a grain that decomposed into fibrous, carbon-rich material and a legume that produces the nitrogen so necessary to healthy plant growth. When they start to go to flower or seed, the crop is slashed and left on the soil surface as a mulch or turned into the upper layer of the soil where it decomposes into the organic matter that improves soil fertility. Alternatively, it can be cut, removed and composted, being returned to the soil as finished compost.

Last winter, a cool season blend of green manure was planted—wooly vetch, a legume, and oats, a grain. The following warm season green manure crop, recently slashed, consisted of Japanese millet and cowpea. Green manures are climate and season specific.

Two interesting things happened around this crop. It was not slashed before the millet set seed, as it would usually have been, and the first of interesting occurrences was an invasion of small, brown birds that discovered they had found an edible windfall and decended on the crop, devouring the seed heads of the millet. These, according to Randwick Council’s bushcare coordinator, were finches. This was not a problem as there were no plans to use the seed and it brought an added wildlife habitat value to the green manure. The second interesting occurrence was also to do with wildlife. One morning, just as council’s sustainability educator, Fiona Campbell, and landscape architect/permaculture educator consultant to council, Steve Batley, were starting their maintenance in the garden, an infestation of small, green, one-centimetre long frogs were observed among the green manure—thousands of them. Perhaps, we thought, this was a simultaneous hatching of eggs that had been laid there. Where all those frogs went remains a mystery… bird food?

Living mulch crops will now be grown in the PIG orchard area to improve soil fertility and discourage weeks. It's a bit like succession in the forest:

  • pioneer species including legumes give the first flush of growth in a cleared area—in the PIG's forest garden area we mimic this with our green manure crops; at the same time, plants that form our windbreak are established—first, the fast-growing arrowroot to shelter the seedlings of olive, pomegranate and citrus that have been planted; then, larger windbreak species including a type of bamboo that can be used for garden structures and whose young shoots can be eaten
  • then, in the natural forest, fast-growing, short-lived species move in to create a new plant mix, a new community, and legumes are part of this plant assemblage too—we mimic this stage of plant succession with our fast fruits and with shrubby legumes like pigeon pea and low-growing alfalfa; the seedlings that will form our mature species tree canopy and edible shrub layer are planted amid these
  • over time, the slow growing fruit and nut trees and shrubs take over the space occupied by out fast fruits of banana, tamarillo, pawpaw and babaco and use more of the soil's nutrient load; the fast fruits continue to be cultivated in areas set aside for them where they are protected from cold, damaging winds in a warm sun trap microclimate to help them get through the winters.

Coming home

This is a course in the cultivated ecology… the model of the natural forest interpreted as a model for the edible forest that feeds people with fresh, good food and that, as a side benefit, provides resources for the wildlife of the area while it supplies the same environmental services as does the natural forest—clean air, infiltration of water into the soil, , the cooling of evapotranspiration from foliage, amendment of the local climate, habitat for wildlife (such as refuge from predators/food via the food web within the food forest) and  with nature, learning about the seasons and nature's cycles, the feeling of being amid living forest. It's a model that serves both people and nature and that, through blending the cultivated, natural and social environments does away with the artificial division between people environment.

Those with historical or anthropological knowledge know that the forest garden is also a home to humanity… it has fed and supplied materials to thousands of generations and in recreating this assemblage of plants and animals, this cultivated ecology, it can continue to do so… they know that, in a sense, creating a forest garden is like coming home… that there's some deep-lying ancestral memory that says—yes, as a species we've here before… and, once again, we can make it so.

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