1901James Fitzgerald acquired the land and it became a dairy farm
1921James Fitzgerald built the 'Cratloe' Cottage, now called the Discovery Centre. The land was sold to Mary Ann and Keith Blow, who shortly afterwards sold it again to Harman Turner Johnson.
1929Arthur Sidney Hoskins purchases 75 acres of land
1937Cratloe Cottage was given to Hoskin's Gardener, Eric Winter.
1939Hoskins completed building his family home 'Gleniffer Brae Manor'. The original garden around the Manor was designed and planted by landscape architect Paul Sorensen and sets the scene for the future inspiration of the Botanic Garden.
1951Hoskins donated 46 acres of the estate to Wollongong City Council for the purpose of building a Botanic Garden. A further 36 acres was purchased by the Department of Housing
1954Glennifer Brae and surrounding areas (15.5 acres) was purchased by the Sydney Church of England Girls Grammar School (SCEGGS). A year later they purchased a further 20 acres from Council
1963Professor Peter Spooner from the University of NSW prepared a master plan for the Botanic Garden, and work began to develop it.
1964The first plantings on the Azalea Bank were installed
1966Council purchased 'Cratloe' and the adjoining 2.5 acres. It became the home of the Botanic Garden Curator until 1978.
1968The Botanic Garden was opened to the public during working hours and in that same year, Council obtained a grant to build the Sir Joseph Banks Glasshouse.
1971Wollongong Botanic Garden was officially opened to the public on 2 January. More than 6,000 people visited in the first year
1975-1978Construction of the walled Rose Garden took place
1978Council purchased Gleniffer Brae Manor and the surrounding grounds
1980Wollongong City Council leased the school buildings and some rooms within the manor house to the Wollongong Branch of the NSW Conservatorium of Music, which took up residence on part of the site. Council used the remainder of the house as a function centre until 2009.
1980sThe Wet Schlerophyll habitat was created. Swamp Mahogany, Sydney Blue Gums and Port Jackson Figs were planted within this collection.

The Woodland Garden was created, with a range of exotic species being planted like Maples, Magnolias, Birches and Dogwoods.

The Dryland Collection, the Dry Sclerophyll Forest, the Herb Garden and the Exotic Rainforest were also developed during this decade.
1983Puckeys Estate Nature Reserve at North Wollongong was named an annex of the Botanic Garden.
1985Gleniffer Brae Manor House was listed on the National Trust of Australia Register.
1987The Botanic Garden took over management of Mount Keira Summit Park.
1988Cratloe Cottage, which had previously been used as a caretaker’s residence, was renamed The Discovery Centre, and used for educational activities.
1988The Friends of Wollongong Botanic Garden presented a custom made Equatorial Sundial as a Bicentenary gift to the city. The Sundial was stolen from the Rose Garden in 2012 but was replaced in 2014.
1991The Friends of the Botanic Garden donated the Woodland Garden Gazebo.
1993The iconic Kawasaki Bridge and Japanese Tea House were presented by the City of Kawasaki to mark the fifth anniversary of our Sister City relationship.
1999Gleniffer Brae Manor House was added to the NSW State Heritage Register. It is now protected under the NSW Heritage Act.