The Gondwana Garden is the latest development in the history of the gardens, which have provided Cantabrians with a tranquil haven away from the trials and tribulations of everyday life for 15 decades.
Based on a traditional English model, the gardens were founded on July 9, 1863 with the planting of an English oak tree that marked the marriage of Queen Victoria's eldest son, Prince Albert Edward to Princess Alexandra of Denmark.
Since then, the Christchurch City Council-owned gardens, bordered by the looping Avon River, have amassed world-renowned collections of exotic and native plants.
With its towering 120-year old redwood monsters, colourful herbaceous borders, and finely manicured lawns, the 21-hectare gardens attract more than 1.1m visitors a year.
Numbers dropped off in the immediate aftermath of the February 2011 earthquake which claimed 185 lives, and shake damage has since temporarily closed some key attractions, including its striking Victorian glasshouse.
But the attraction rebounded last year, and has never been more popular with quake-affected locals keen to find some peace and beauty away from their disrupted lives.
A new $16 million glass visitors' centre is being built this year and Dr Clemens wants to continue the progressive work done by generations of curators who came before him.
"It's been a landscape of change over the last 150 years and we want to continue moving and pushing forward."
Dr Clemens says it's important to adhere to the gardens' ethos of "holding documented collections of living plants for the purposes of scientific research, conservation, education and display".
But he also wants to move with the times, and continue to be relevant with younger, increasingly high-tech generations.
Plants labels, for example, which reveal names in Latin, English and often Maori, and where the plant originates, could also feature electronic bar codes that can be scanned by smartphones, to give more interactive experiences.
"We're forever adding new plants and new species from around the world," Dr Clemens said.
"We continually trying to come up with new ideas, and we have to if we want to be around for another 150 years."
Christchurch Botanic Gardens timeline:
1863 - July 9, officially founded by planting of Prince Albert Edward oak
1871 - Pine Mound planted with Pinus pinaster and seed of Sequoiadendron giganteum received
1898 - Major fire destroys 5.5 acres of land
1910 - The first fete is held, attracting a crowd of 20,000 to 25,000 visitors
1924 - Victorian conservatory Cuningham House opens
1944 - Paddling pool constructed in the Children's Playground
1968 - April 11, 'Wahine storm' causes extensive damage
2011 - February 22, magnitude-6.3 earthquake damage gardens buildings
2013 - 150th anniversary celebrations