Marion Mahony and Walter Burley Griffin's love of nature was life-long and spanned multiple continents. When Marion was a child her family moved to Hubbard Woods on the shores of Lake Michigan. There, her parents gave their children free rein to explore 'Mother Nature's paradise’, and Marion took great pride in her ability to scale trees of any height. Similarly, Walter's family members recalled him patting the plants and flowers in his family garden as a child. After success in the Federal Capital Design Competition in 1912, the Griffins travelled to Australia and were instantly captivated by the Australian flora.

When selected as the site of the Federal Capital, Canberra was far from the bush capital people know today. A 1918 Afforestation Report described the pastoralists who had settled on the site as the 'worst enemy of the real forest country.' They had cleared the land of native vegetation and left it barren and rabbit infested. In 1913, horticulturist Thomas Charles George Weston (1866-1935) was appointed as officer-in-charge of afforestation and tasked with rehabilitating the site.

From barren pastures to bush capital

In their plan for the future capital, the Griffins proposed allowing the mountains to retain their natural state as 'forests or game preserves.' These mountains were significant to their overall design, with the lines between them forming key axes across the city. The resulting design embraced the site's natural contours instead of flattening them, working with the environment instead of against it.

Walter dreamed of painting the hills. He wanted 'to plant each hill with a distinctive colour, one with reds, another with blues, another with yellow and gold and so on.' This project required detailed knowledge of Australian flora. Unfortunately, as Marion bemoaned to a friend, this information was not readily available to them at the time. To remedy this, the Griffins compiled eight colour-coded volumes describing the various species of Australian native flora. In addition to the copy held by the Griffins' office, a typed copy of the meticulously compiled content appears in the National Archives' collection.

In his years as Federal Capital Director of Design and Construction, Walter worked with Weston to try and bring this dream to life with varying degrees of success. Drought, in particular, caused significant difficulties, and Weston reported the death of many of the plants.

Today finding traces of these plantings is a challenge; however, on Red Hill, some of the original Callistemon and grevillea can be found and are cared for by a group of local people called the Red Hill Regenerators. In 2018 the site was added to the ACT Heritage Register.

Unusual specimens

Although the Griffins preferred to use native Australian flora, some exotic specimens found their way to Canberra. With the intention that the trees would eventually produce a profit, a plantation of Quercus suber, or cork oaks, native to North Africa and South-West Europe, was established at Green Hills. Today this site forms part of the National Arboretum, with the site still yielding cork to this day – the first cork harvest taking place in 1948.

Near the Canberra airport in the suburb of Pialligo, another unusual forest can be found – one of North American Coastal and Giant Redwoods. Central to the Griffins' proposal was a series of constructed lakes. To the east of these was a further, more organically formed lake. The redwood forest would sit on the lake's northern edge. Unfortunately, the drought that caused so many difficulties with the other Griffin plantings also affected the redwoods, which required much more water to thrive. Of the 122,000 that were planted, only 3000 survived. Today a 3-kilometre track winds through the forest.