Introduction
Sustainable gardens evolve over time – this is a good example of a garden that has changed as the owners’ interest in sustainability has developed. Edwina Richardson is a Landscape Architect who has a keen interest in the sustainability of the built environment.
The aims of the garden design for the a family with two young boys and two dogs, were multiple. Richardson wanted to grow a range of food plants, attract native birds and provide secret spaces in the garden for children's play. As her ideas about design and sustainability crystallised, Richardson focused on creating a sustainability aesthetic appropriate to the Canberra Region. Native and exotic plants were chosen for their visual appearance and hardiness and most of the hard materials in the rear garden were reused from the site.
Front Garden
The front garden was developed in 2000, incorporating existing mature plants such as Rhododendron, Laurus nobilis (Bay tree), Camellia and a Pyrus ussuriensis (Manchurian Pear). These were supplemented with both native and exotic plant material. With government approval, the grass nature strip was removed and plant material extended to the footpath. Low growing hardy plants such as Lomandra longifolia, Lomandra ‘Katrinus’, Correa ‘Dusky Bells’, Philotheca myoporoides, Brachyscome multifida, Grevillea ‘Forest Rambler’, Dianella tasmanica and a native Pelargonium were massed replacing the lawn. The indigo berries of the Dianella provide food for hungry Crimson Rosellas in Summer. These birds cling nimbly to the stems creating temporary movement and colour to the shrub beds.
A hedge of Lonicera nitida which flanks the curving entry path, was established from cuttings and Acer palmatum, Phormium ‘Atropurpureum’, Ophiopogan japonicus, Ajuga and Dicksonia antarctica were introduced.
Passive cooling
The front garden faces east and provides glimpses to nearby wooded Mt Majura. The mature Manchurian Pear, a deciduous tree well suited to Canberra’s climate, provides protection from the hot summer sun and helps cool the front garden and the front of the house. An existing concrete front patio was extended using concrete unit pavers set in gravel. This permeable surface allows water to percolate slowly into the ground and evaporate as the day heats up. The aim is to maintain this lush green character of the front garden. Summer easterly breezes usually arrive in the early evening and help to draw cool air from the garden into the house assisting in passive cooling. Renovations proposed for 2007-2008 aim to channel more of this cool air into the building.
Rear Garden developed in stages
The north-west facing rear garden has undergone major changes since 2004 after Richardson prepared a much needed Landscape Sketch Plan. It includes a series of garden rooms: an outdoor terrace, smaller terrace, basketball area and a mulched open space enclosed by shrub beds. Features within the garden include a boardwalk and dry creek bed and an attractive workshop. Open space and garden features are balanced with densely planted shrub beds with a layering of plants from small trees, shrubs, groundcovers, accent plants, climbers, perennials and bulbs.
Lawn is absent from the garden, as there are a number of nearby public open spaces, such as Mt Majura Nature Reserve, a two minute walk from the house and the well irrigated Hackett oval, about a five minute bike ride away. |
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An area of permeable paving creates an open courtyard like feel to the front of the home. Lawn is replaced with a combination of native and exotic plants, such as Lomandra 'Katrinus', Phormium 'Atropurpureum' and Rhododendron which add to the lush feel of this space. |
Outdoor Terrrace
The first space developed was an outdoor terrace which captured winter sun with strong links to the deck and living areas of the house. The paved area was built from unit pavers and bricks from the site and was enclosed by a plant palette suitable to Canberra’s hot dry summers and frosty winters.
A generous square of paving was set at a 45 degree angle to the house, mimicking the diagonal lines of the deck, living room and kitchen. Large 600x600 grey concrete pavers, previously laid as the driveway, were relaid in a grid pattern. A simple but effective inset of ‘Old Canberra Reds’ provides interest in the terrace. These bricks had been removed from the chimney during renovations. Paving was laid on a compacted layer of crushed cement (a recycled locally available product) and sand.
An experimental mix of mainly hardy native and exotic plants were chosen which thrive on a low water regime once established. Plants were chosen for their form, foliage and textural characteristics rather than seasonal colour. Two sides of the space were enclosed by a hedge of Westringia ‘Wynyabbie Gem’, with its fine foliage and delicate mauve flowers backed by Dodonea viscosa ‘Purpurea’. Unforunately the Dodonea 'Purpurea' hedge failed to thrive and was replaced in 2007 with Callistemon 'Endeavour'. Drought hardy Mexican Orange Blossom, Choisya ternata, is massed to repeat existing Choisya which have thrived despite ongoing drought.
An eclectic combination of silver foliaged plants were used around a terracotta water feature including Artemesia arborescens (Tree Wormwood) and Artemesia ‘Powis Castle', the native Leucophyta brownii (Cushion Bush) as well as Sedum and Dietes. Prior to planting the soil was improved with a combination of aged horse manure, straw and home made compost to ensure the success of plant development in future years despite continuing water restrictions. Feature pots are planted with drought hardy succulents with strong architectural form such as Echeveria and Aenonium ‘Schwartzkopf’.
Sound and movement were introduced by using a simple water feature. A solar pump and fountain were placed inside a large terracotta pot – functioning only when the solar panel is exposed to direct sunlight. This feature is backed by a screen of timber and corrugated iron – re-used from a display garden at Floriade 2003.
In keeping with the theme of a low environmental impact, whimsical candle powered lanterns are nestled amongst the plants which are only lit at night when the outdoor space is being used.
The pine boardwalk links to the terrace of reused concrete pavers and 'Old Canberra Red' bricks. Reused river stones provide an effective mulch and are useful for deterring dogs from garden beds. Photo Edwina Richardson.
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Workshop
An existing poorly located garage (brimming with household items) was converted into a workshop. In late 2005 a carpenter was engaged to cut the garage in half. The front portion was clad in corrugated iron and re-used timber and glass doors installed. This created a big difference to the feel of the garden. A group of mallee Eucalypts, Eucalyptus mooreii have been mass planted in front of this structure and will eventually allow glimpses to the workshop and also provide much needed shade to the west facing deck.
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Boardwalk and dry creek bed
The boardwalk was designed and constructed in early 2006 from radiata pine. This structure traverses the slope and links the outdoor terrace to the deck. A dry creek bed, filled with waste rock, snakes down the slope terminating in a shallow detention basin under the deck. Native wetland plants, Juncus usitatus and Ficinea nodosa are planted within the drainage line to provide interest in this area and are watered with grey water. A chain from the rear deck directs rainwater from the pergola roof into the dry creek bed during rainfall.
Plant material
Overall plant material is chosen for its drought tolerance and in 2005 Richardson began introducing species occurring in the nearby Eucalypt woodland/forest of Mt Majura. A number of Cassinia longifolia, an attractive local shrub, have been massed near the rear fence for screening purposes. Dodonea viscosa, a shrub found on Mt Majura has been propagated by seed and is growing rapidly and lushly in the garden environment. Richardson believes this plant has potential for use as a relatively fast growing hedge in the Canberra district, replacing plants like Pittosporum.
Native to the Canberra region, tubestock of Acacia rubida and Banksia marginata have also been added to create privacy in the garden and food sources and niches for wildlife.
Eucalypts were introduced into the garden reflecting Canberra’s dominant vegetation form. These include Eucalyptus gregsoniana, Wolgan Snow Gum from the Braidwood district, E.mooreii, White Sallee and E.stellulata, Black Sallee. These were purchased as tubestock and some specimens have grown as much as two metres in height in the first couple of years.
Native grasses and forbs (non-woody flowering plants) which occur locally in eucalyptus woodlands and forests such as Bulbine bulbosa, Stylidium graminifolium, Calocephalus citreus, Chrysocephalum, Wahlenbergia, Dianella revoluta and Themeda triandra were planted in terracotta planter boxes. This trial aimed to see which plants would perform well in a garden situation. The Dianella revoluta has proved particular hardy and the Wahlenbergia have spontaneously colonised gaps between the pavers.
Permanent edible plants incorporated within the garden beds include citrus (cumquat, lime and kaffir lime), olive, hazelnuts, feijoa, fig, bay and artichokes. Hardy herbs such as rosemary, sage, thyme and fennel jostle amongst more ornamental plants. A number of fruit trees remain in the garden from the original owners, such as a prolific thorny lemon, a pear and two plum varieties. The banana passionfruit, a vigorous climber, grows up the north wall of the house. Bush food plants like the native lily pilly, Syzygium and the locally occurring Tasmannia lanceolata (Mountain Pepper Berry) are included in the garden. Vegetables are grown in a small raised garden (2.4m x 2.4m) and in a multitude of pots. Richardson enjoys growing unusual varieties of heirloom vegetables. One of the prettiest of these is a Snow Pea, which bears a two tone mauve flowers, not unlike a sweet pea, followed by yellow edible pods.
Habitat
One of the earliest aims of the garden was to encourage birds into the garden. This has been partially successful – the garden is favoured by larger dominant birds such as Noisy Miners, Currawongs, Wattle Birds and Parrots. Smaller birds are rarely sighted, however this may improve as some of the dense native plantings mature.
As the owners adhere to organic principles, there are a diverse array of insects in the garden which provide great delight and a food source for insectivorous birds. In Spring, masses of Hover Flies create a gentle humming sound. Small skinks dart in amongst protective rocks and straw mulch.
Irrigation
The rear garden was recently converted from spray to drip irrigation, using a mix of in-line drip irrigation and individual drippers. These were buried under a coarse mulch product. A portion of the garden planted with Lomandra 'Katrinus' and wetland plants set in gravel is watered using grey water from the bath and/or laundry. The owners’ are conscious of the products they use for washing clothes and have converted to using washing powder low in salts and phosphorous. They also use organic olive oil soap and shampoo in the bathroom. These products are free from palm oil, detergents, scents and colours.
Landscape Materials
Richardson’s philosophy has been to use materials which echo rural buildings as well as the colour of local geology. Locally sourced waste rock is used for the ‘dry creek bed’, and as mulch for terracotta pots. The rounded river pebbles which formed the central aisle of their driveway, are re-used as mulch. All the large concrete pavers were re-used from the site. The ‘Old Canberra Red’ bricks used as an inset in the terrace paving feature, for plinths and for the small herb garden, were removed from the house during renovations. Richardson’s husband, Craig, has performed most of the landscape construction greatly reducing the overall cost of the garden.
Maintenance
Maintenance of the garden is ongoing as the garden continues to evolve. Nurturing the garden is part of the joy of creating it. The soil is improved with worm castings, manure, compost and ‘Forest Litter’ (recycled green waste) breaks down to add more organic matter to the soil. Plants are tip pruned after flowering to maintain a compact form.
Conclusion
The garden has developed slowly and continues to evolve. The owners plan to convert the front garden to drip irrigation as spray irrigation is banned under current water restrictions. With a further renovation planned they hope to introduce a simple grey water system using reed beds and water tanks to become more self-sufficient in resource use in the garden. They have aimed to create a new Canberra landscape aesthetic – a garden reflective of the local environment, with a low ecological impact and outdoor spaces that provides year round interest for family, visitors and clients.
>> For more images of the garden
Edwina Richardson AILA 2007
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