Completed in 1841, the Great Conservatory was the largest glasshouse in the world: an extraordinary feat of Victorian engineering designed by Joseph Paxton to cultivate plants from across the globe in the Derbyshire climate.

In this film, Steve Porter, Head of Gardens and Landscape, and Faye Tuffrey, Garden Collection and Learning Manager, explore the ambition behind the Conservatory. 

Discover how the Conservatory's ingenious heating system worked, the remarkable plants it enabled Paxton to cultivate, including the banana that would become the Cavendish, and the surviving traces of this extraordinary building that can still be found in the Chatsworth landscape today.

Video Transcript

In 1841, a vast glass structure stood in the gardens at Chatsworth. It measured nearly 100 metres in length, over 60 feet high, and covered more than an acre.

At the time, it was the largest glasshouse in the world. Inside, tropical plants grew year-round, in the climate of northern England. This was the Great Conservatory.

It was created by Joseph Paxton, head gardener at Chatsworth, working for the 6th Duke of Devonshire. The Duke funded plant-collecting expeditions across the globe. Paxton’s task was to keep those plants alive. As Paxton later put it, the aim was simple: 

“To bring together, under one roof, the vegetation of the tropics.”

The building was constructed using iron ribs, timber framing, and large sheets of glass. Its scale was deliberate. A larger internal volume meant slower temperature change. The curved roof maximised light exposure across the day.

Nearly 70,000 square feet of glass were used in its construction. Visitors remarked that it resembled “a crystal palace in a garden”, a description that would prove accurate a decade later. 

The Conservatory was, above all, a heating system. Eight coal-fired boilers supplied hot water to approximately seven miles of pipe. These ran beneath the planting beds, maintaining a constant tropical temperature. 

It required around 300 tonnes of coal each year to operate. Coal was delivered through underground tunnels. Workers maintained the fires continuously. Without that input, the system failed.

Images 1-3: The Great Conservatory. Image 4: The coal tunnel entrance in the garden. Image 5: Chimney in Stand Wood.

Inside, the planting was designed to be immersive; a constructed landscape. Visitors described it as:

“A dense and luxuriant jungle… beneath a vault of glass.”

Palms, tree ferns, and flowering plants were arranged to control movement and sightlines. It combined botanical experimentation with deliberate spectacle.

The Conservatory made reliable tropical cultivation possible in Britain. Species that would not survive outdoors could now be grown, studied, and propagated. One, in particular, would have lasting significance.

One of the Great Conservatory's most famous residents was the Cavendish banana. After first flowering at Chatsworth in 1835, the variety was propagated by Joseph Paxton and planted throughout the Conservatory. 

Its true significance came much later; when Panama disease destroyed the dominant commercial banana in the twentieth century, the Cavendish was adopted as its replacement. Today, it is the banana found in supermarkets around the world.

One of the oldest plants in the Great Conservatory was a tree fern – Dicksonia antarctica. It was one of the original plants first imported from Australia in 1826.

When the Great Conservatory was demolished in 1920, it was moved to another glasshouse at Chatsworth, where it grew until it reached the roof. Since then, it’s been moved twice more and now stands happily in our Display Glasshouse.

Many economic plants were also grown here; orange and lemon trees, sugar cane, cinnamon, cardamom, coffee and pepper. In 1891, it was described as being visited by 50 000 people a year, since 1840s. Open for free admission, every day except Sundays. For most people, this would be their only chance to experience these tropical plants.

Image 1: Tree Fern in Display House. Image 2: Cardamom growing in the Display House.

The Great Conservatory demonstrated that large-scale environmental control was achievable. It combined horticulture with industrial systems - heat, materials, and prefabrication.

Within a decade, Paxton would apply these ideas to a building on a vastly larger scale: The Crystal Palace.

But the Conservatory depended on constant energy. When the First World War restricted coal supplies for non-essential purposes, heating could not be maintained. Temperatures dropped. The tropical planting - built up over decades - was lost. In 1920, the structure was dismantled. 

At its peak, it had been the largest glass building in the world. Within 80 years, it was gone.

Very little remains today; the walls (now surrounding the Maze), the coal tunnel, the large chimney in Stand Wood. But its influence persists: in modern glasshouses; in controlled growing environments; and in the global movement of plants.

The Great Conservatory was an experiment in scale, climate, and control. An experiment that worked.  Now, the glasshouse is gone, but it's legacy remains.