Botanic Gardens glasshouse emptied out for $10m upgrade

The plants have almost been completely removed from Cuningham House at Christchurch's Botanic Gardens ahead of the historic glasshouse's $10 million upgrade.

The neo-classical style display house next to the Central Rose Garden was home to a substantial collection of tropical plants, most of which have been carefully relocated to the Townend and nursery glasshouses.

Botanic Gardens and garden plants director Wolfgang Bopp said just five plants will remain in Cuningham House during the restoration work.

"This is a process we call decanting and it’s not just about shifting plants; besides moving many hundreds of potted plants, we’re also working on the collection during this time for the benefit of the plants and the future planned display.

"The plants in the central bed will be lifted and potted and grown on in the other houses.

"These are plants that have grown together, been shaped by one another and formed a unique ‘landscape’ within the glasshouse.

"It’s a big job because overall there could be up to 3000 plants in total but it's hard to estimate because when they are growing in masses or in the same container, that makes it difficult to distinguish individuals."

Two male and female miniature date palm trees, Phoenix roebelenii, will remain on either side of the entrance during the upgrade.

Bopp said it is likely the slender 6m tall palms are the same ones that appear in pots in a photo of Cuningham House taken around the time it opened 100 years ago. 

The century-old palms will be surrounded by protective scaffolding and covered with protective film while the restoration takes place around them.

An eight to 10m nikau will also remain at the site.

Staff estimate the slow-growing native to be between 30 to 40-years-old but due to warm, moist conditions inside the glasshouse, it’s much larger for its age than if it had grown outdoors.

"For plants that are easy to propagate like the banana plants, they send out baby shoots quite regularly, we will dig up several and pot them up, ready to grow into mature plants for replanting when Cuningham House is completed," Bopp said.

"We have already moved several large potted plants into Townend House. 

"We’ve also contacted other botanic gardens in Aotearoa to share some of the plant material with them.

"To share experience and knowledge a staff member from Wellington Botanic Gardens has recently spent a couple of days with us and she has taken plants back to enrich their own collection.

“Giving rare or unusual plants to other botanic gardens is a type of insurance policy, in case anything happens to the parent plant." 

The restoration of Cuningham House is expected to take 18 to 24 months and cost about $10 million.