Walling was born in Yorkshire and grew up in the village of Bickleigh in Devon, England. When she was fourteen years old she emigrated to New Zealand and three years later moved with her family to Melbourne, Victoria, Australia.
Walling studied horticulture at Burnley College and after some years as a jobbing gardener she commenced her own landscape design practice in the 1920s, and "went on to design some significant Arts and Crafts gardens".
In the 1920s, Walling began to develop a village at Mooroolbark on the outskirts of Melbourne called Bickleigh Vale. With its unique collection of charming houses and gardens Bickleigh Vale is one of her most acclaimed achievements. It was designed to be 'the nucleus of an English village' and she built the first cottage, named after the village of Sonning on the River Thames in England, as her own home. She sold subdivisions of the land only to people who were prepared to accept designs for cottage and garden prepared by her. In 1935 Walling's assistant Miss Crouch had her hands 'severely cut' breaking a window to free two cats after a fire started at Sonning.
In 1935 Ellis Stones built a wall for her. Recognizing his ability—which she called 'a rare thing this gift for placing stones' - she suggested that he work for her. She gave him a free hand to create walls, outcrops, pools and paths in her gardens at some of Melbourne's finest homes. Their best collaboration was seen in a free-form swimming pool and outcrop, built in 1939-40 for Edith Hughes-Jones at Olinda, Victoria
In 1926, Walling began contributing regularly to Australian Home Beautiful. Her design practice grew and she worked across Australia, in Perth, Hobart, Sydney, and Buderim in Queensland. Her Victorian commissions included designing the lily pond for Coombe Cottage, Dame Nellie Melba's residence in Coldstream, in the Yarra Valley Ranges; Durrol for Mrs Stanley Allen at Mount Macedon; Cruden Farm garden for Mrs Keith Murdoch (later Dame Elisabeth), Langwarrin (Gardening Australia website: Cruden Farm). One of her most intact NSW commissions is Markdale, Binda (). Her plans from the 1920s and 1930s show a strong architectural framework with 'low stone walls, wide pergolas and paths – always softened with a mantle of greenery'. She later drew inspiration from the Australian bush, creating a more naturalistic style with boulders, rocky outcrops and indigenous plants. In small suburban gardens, Walling created garden 'rooms' in order to make the garden appear far larger than it actually was.
Her designs were heavily influenced by her experience of the Devon countryside as a child and designers such as Gertrude Jekyll.
She was the author of several books on landscape design:
- Gardens in Australia 1943,
- Cottage and Garden in Australia 1947 and
- A Gardener's Log 1948
In the 1950s, Walling became interested in the conservation of roadside vegetation and was a prolific writer in the press on the subject as well as her 1952 book The Australian Roadside. According to Trisha Dixon, Walling was an important influence on Australian gardening, steering tastes away from an Anglo-centric heritage towards a respect for the Australian climate and landscape.
In 1967, she moved from Melbourne to Bendles at Buderim in Queensland, where she had hoped to further develop the village concept but it did not progress. Despite her ill-health during her last years at Bendle, Walling continued to write prolifically, rewriting manuscripts, corresponding to newspapers on environmental issues, and trying to republish her books. About a quarter of Walling's designs survive and these are held in the State Library of Victoria and in private collections in Tasmania, South Australia, New South Wales and Victoria.
- "Fact Sheet: Bickleigh Vale". Gardening Australia. Australian Broadcasting Corporation. Retrieved 2008-09-07.
- Vale, Anne. "Walling, Edna". Australian Women's Archives Project 2014. Retrieved 5 May 2014.
- "OLD HOME BURNT.". The Argus (Melbourne, Vic. : 1848 - 1957) (Melbourne, Vic.: National Library of Australia). 22 June 1935. p. 26. Retrieved 30 August 2013.
- Dixon, T., 'Walling, Edna Margaret', in R. Aitken and M. Looker (eds), Oxford Companion to Australian Gardens, South Melbourne, Oxford University Press, 2002, pp. 625-26.
- Dixon, T., 'Still on the trail of Edna Walling', Australian Garden History, 22 (1), 2010, pp. 21-22.
- Australian Women biographical entry for Edna Walling
- Edna Walling website produced by Tantamount Productions and the State Library of Victoria for the Australian Broadcasting Corporation (ABC)
- Edna Walling's Manuscript
- Edna Walling entry in The Encyclopedia of Women & Leadership in Twentieth Century Australia