The gardens were founded in 1863 when an English oak was planted to celebrate the marriage of Prince Albert (later Edward VII) and Princess Alexandra of Denmark. That tree still grows in the 21 hectares that sprawl along a loop of the Avon River, adjacent to Hagley Park. The early history is full of surprises. The Canterbury Acclimatisation Society once operated a small zoo on the grounds that included, improbably, a California grizzly bear. European fish and birds were introduced to test how species from around the world would adapt to New Zealand conditions. When the Acclimatisation Society relocated in 1928, the land folded back into Hagley Park, and from 1933 daffodils were planted where the zoo animals had once roamed. By then the gardens had already hosted an International Industrial Exhibition in 1882 and attracted crowds of up to 25,000 to their first domain fete in 1910.

The gardens hold a remarkable range of plant life across multiple specialized collections. The Central Rose Garden, first established in 1909, was once considered the largest and finest in Australasia, with 132 beds and nearly 2,500 rose bushes. It has been redesigned twice since -- first in the 1930s around a circular mirror pool, then in the 1950s with a memorial sundial -- and now supports 104 beds of climbing, standard, and Hybrid Tea roses. The New Zealand Garden, established between 1910 and 1927 by curator James Young, offers walks beneath canopies of kahikatea and beech. A separate Icon Garden features silver fern, harakeke, rimu, and kotukutuku. In the conservatories, Cuningham House -- built in 1923 and heritage-listed -- drew long queues in 2020 when a rare corpse flower bloomed for the first time. Garrick House contains New Zealand's most extensive publicly owned collection of cacti and succulents.

The gardens carry layers of memorial and commemoration. The Bandsmen's Memorial Rotunda, opened in 1926 by MP Sir Heaton Rhodes, honors military musicians lost in the First World War. Rhodes, a colonel himself, recalled that after Gallipoli only one band could be formed from the four that had sailed to the battle. Until the 1950s, brass bands played regular Sunday afternoon concerts there. The Kate Sheppard Memorial Walk, created in 1990, honors the suffragist who led the campaign that made New Zealand the first country to grant women the vote. Canterbury women's groups donated 100 white camellias -- the symbol of the movement -- to line the walk, and in 1993 a new camellia cultivar named Kate Sheppard was bred to mark the centenary. In 2006, the New Zealand Peace Bell, a 365-kilogram bronze bell inscribed in English and Japanese, was installed in a pavilion blessed by Ngai Tahu. A sculpted piece of pounamu, gifted by the iwi, rests in the reflection pond beneath it.

Despite earthquakes and tragedy -- the 2011 quake damaged the tea kiosk, and after the 2019 mosque shootings, mourners lined the gardens' walls with flowers, cards, and teddy bears -- the Botanic Gardens remain Christchurch's green anchor. Up to forty species of native and introduced birds shelter here and in adjacent Hagley Park. The kereru, with its glossy green plumage and distinctive thudding wingbeats, plays a critical role in native forest renewal by dispersing large seeds. Bellbirds call from the canopy. Fantails flit acrobatically in search of insects. Near the playground, a Wollemi Pine planted in 2013 represents a species that dates to the Jurassic period -- the first of its plantings in New Zealand. The Ilex nursery, attached to the visitor centre that opened in 2014, propagates 10,000 plant species to supply the conservatories and preserve diversity. What began with one oak tree for a royal wedding has become a place where the deep past and the living present share the same soil.