While many gardens are well on their way to achieving water sustainability, some are still in the initial planning stages. Royal Botanic Garden Sydney hopes to someday become a more waterefficient garden by using graywater from the city’s nearby tunnel system. RBG Sydney currently buys all of its water from the city in the form of potable water, which is expensive and ultimately detrimental to the plant collections during droughts when there are water restrictions. With significant changes in infrastructure, the garden could potentially use graywater from the city’s nearby tunnel system. This would eliminate the need to use valuable potable water for irrigation, be less expensive after the infrastructure is in place, and reduce the hazard of drought damage to collections. However, this massive change in infrastructure would require a large capital campaign and significant leveraging of city partnerships, both difficult tasks for a garden that is striving to gain financial independence. C. Climate Change Climate change was an underlying theme at all of the institutions visited, although some organizations addressed it more directly than others. For example, RBG Melbourne has built their new water-use plan on the 2090 Climate Projections and is working towards adapting their garden to the hotter and drier climate being predicted for the region. The seed banks at Adelaide Botanic Garden and Australian Garden Mount Annan also attest to each garden’s efforts to preserve plants in the face of climate change. Adelaide’s South Australian Seed Conservation Centre (Figure 14) is attempting to collect seeds from as many native plants in the state as possible before climate change drives them to extinction, while the labs at Mount Annan’s PlantBank are continuously doing research on projects such as native seed germination under hotter climate conditions. In fact, the PlantBank is currently conducting research to study how seeds will react to increased temperatures using a Gradient Plate for seed germination efficacy testing that can regulate a spectrum of heat across a surface (Figure 15).
All of the visited institutions accepted climate change as a reality to be managed instead of a controversial debate. Gardens subtly interpreted climate change as fact to guests within the gardens, something not usually seen in American gardens. With this outlook, Australian gardens are addressing climate change in two ways; by acting as positive environmental stewards in their own organizations, and by creating new generations of environmental stewards through connecting Australian citizens with the natural world.