Delprat Cottage and Garden

The Hunter Valley is home to over 1000 toxic sites, with fifty located within Newcastle’s Local Government Area. Delprat Cottage and Garden sits on the fringes of the former BHP steelworks in Newcastle, 165km north of Sydney, Australia. Set on five acres of post-industrial wasteland, life has been breathed back into this toxic landscape with the transformation of the grounds into phytoremediation gardens to cleanse the soil and regenerate the land. Once the site of one of the biggest employers in the area, the steelworks operated for 84 years, closing in 1999, but not before a bevy of toxins contaminated the soil and groundwater from the heavy industrial use. This unique experimental biotechnical design project at Delprat Gardens reinstitutes regimes of care by exploring the use of phytoremediation and the ability of plants to absorb and remove toxins from the soil. During the process, new discoveries about the plants’ natural restoration capabilities are being revealed and recorded whilst thriving in an unnatural, contaminated environment. The design research team created four garden designs: flowering meadows, a kitchen garden, orchards with underplantings, and a cottage garden surrounding the heritage listed cottage. Each garden typology is sown with varieties of Australian native and introduced, exotic species. The kitchen garden includes annual and perennials herbs, vegetables, fruits, and flowers. The implications of edible plants and pollinators absorbing toxins ensures popular attention to this garden. The cottage garden is inspired by the adjacent neighbourhoods and Edna Walling’s gardening ethos, celebrating the textures and colours of native plants in curated compositions. The orchards or tree groves are longer-term plantings to determine sustained cleansing abilities and resilience. They also provide insight into the potential of future street trees to thrive in toxic soils under high temperatures and less water due to climate change. The meadows are an example of broad-acre style planting, involving a low-cost planting method of annual and perennial grasses and flowering meadow species. This portion of the site is an example of how land developers can remediate larger acreage brownfield sites. The data collected records not only the toxin/s absorbed, where the toxin might be stored in the plant, but also which plants might be safer to ingest for both humans and animals. The findings and results are published publicly, open access, on the Delprat Garden website, as well as a DIY Phytoremediation Garden guide promoting and educating others about phytoremediation. The gardens impact thus far are ground-breaking in terms of native Australian plant species and their phytoremediation properties as well as successfully reducing dangerous toxin levels in the meadows which now meet Australian standards. An environmentally sustainable and low-cost method of regenerating contaminated soil using sunlight and plants, this project has converted a previously unused and neglected site into a living laboratory, activated with scientists, researchers, school children, garden clubs and the public through open days, events and site visits. The garden celebrates phytoremediation techniques as productive ecologies, restoring degraded land in a beautiful, expressive, and educative manner.