From the first official survey carried out for the map of Adelaide, Colonel William Light intended for the planned city to have a "botanical garden".

To this end, he designated a naturally occurring ait[citation needed] that had formed in the course of the River Torrens, in what is now the West Parklands.

[3] The South Australian Agricultural and Horticultural Society (formed 1842) and other groups continued to press for the creation of a public garden.

The land was held sacred by the Kaurna people as the red kangaroo dreaming (Tarndanyangga), but at that time it was being used as paddocks for police horses.

Francis was responsible for establishing the perimeter, solving the flooding problems and landscaping North Terrace to blend well with the entrance to the garden.

In October 1855 he presented his first progress report, including a plan of Regent's Park in London as an example of circular garden design that he thought could be adapted for Adelaide.

[4] A pagoda was built in 1863, and Francis established the first herbarium and botanical library in Adelaide in 1864, a rustic temple modelled on the Museum of Economic Botany at Kew Gardens in England, with the design imitating the Parthenon in Athens.

He proved so successful that public service regulations were waived to extend his directorship (and occupancy of the Lodge) past mandatory retirement age.

[17] The restoration works were assisted by a grant from the Government of Australia for $1.125 million[18] and sponsorship by South Australian oil and gas company, Santos.

[24] Among other scientific and educational displays of native and international horticulture, the gardens hold one of the earliest propagated specimens of the Wollemi Pine tree, which was discovered as recently as 1994.

The conservatory originally housed at-risk or endangered tropical rainforest plants from northern Australia, Papua New Guinea, Indonesia and south Pacific Islands.

[27][28] In April 2012, the entry fee to the conservatory was abolished, despite rising energy costs and budget cuts resulting in the building no longer being heated.

[citation needed] In order to reduce the garden's reliance on potable water from the River Murray, a new wetlands system was constructed south of the Bicentennial Conservatory to hold stormwater diverted from First Creek.

The wetlands form part of an aquifer storage and recovery system which is expected to have a usable capacity of 100 megalitres (22,000,000 imp gal) per year,[31][32] enough to water the entire Botanic Garden.

[33] The 2.6-hectare (6.4-acre) site also features a trail of interpretive signage, tiered garden beds showcasing aquatic plants and three large ponds with reed-beds which support a diverse range of native wildlife.

Funds are raised for the purposes of "scientific research, education, acquisition and maintenance of living collections and for the long-term financial security of the Gardens."

[40] The demolition of a couple of non-heritage buildings in the old Royal Adelaide Hospital site has meant that parts of the garden need to be blocked for safety reasons.