By Emma House, Curator
I’ve never owned a greenhouse, my little town garden is too small to accommodate one but glasshouses have always held a fascination for me and some of my favourite items in the museum are artworks and photographs featuring gardeners tending plants in their greenhouses. On any garden tour I always love to see what people are growing in them. I was therefore delighted to join some of my colleagues to visit the newly restored glasshouses at Chelsea Physic Garden which have been reopened as part of the garden’s 350-year anniversary celebrations.
The Glasshouses were designed by Foster and Pearson and built in the early 1900s. They were made from Douglas Fir and Burmese teak. As the latter is now a protected material and the team at Chelsea Physic Garden are committed to working sustainably they carried out repairs with UK grown sweet chestnut. As much of the original structure was retained as possible during the restoration with new timber being spliced where required with existing timber. Original cast iron window winding mechanisms and door furniture were repaired. In total 204 individual fittings were removed, restored and put back in situ again. The special horticultural glass which allows more light to pass through than regular glass was carefully taken off, cleaned and replaced.
One of the things that interests me about greenhouses is the technical skill and invention they always seem to encompass. An ink and wash drawing of a greenhouse in the Garden Museum’s collection dating from the late 18th century illustrates the heating system that circulates the building with stoves and flues around the perimeter. The draughtsman adds a puff of smoke with a flourish on the external wall, I think almost like a full stop that draws the viewer to its design ingenuity.
At Chelsea Physic Garden modern technical innovation has sympathetically been introduced to the historic glasshouse. In the Tropical corridor a misting system has been added to enable them to care for plants that naturally live in more humid environments. A rainwater harvesting system has also been included that will reduce water consumption and assist with the garden’s sustainability aspirations. Automatic door closures have also been introduced and well-planned paving to allow visitors with mobility issues easier access.
The project passed on valuable skills to a new generation of craftspeople with over 2,500 hours of training being provided to apprentices. Two horticultural students were also given the opportunity to develop expertise during a two-year Glasshouse Horticulture Trainee programme.
The glasshouses are home to over 1200 plants from 817 plant species. During the project 157 new plants were added to the collection. For the first time interpretation panels have been added to the glasshouse which provide information on the plants and their histories. They introduce themes that include plant diversity and adaptation, gardening in the climate crisis and ethnobotany.
In the Tropical Corridor there is a Cinchona pubescens or fever tree, the bark of which is used to produce quinine which people in South America used to treat fevers for hundreds of years. New labelling explains how European colonisers utilised its properties to treat malaria in Europe but subsequently introduced malaria to South America where people had little resistance.
Labelling for the Vanilla planifolia (vanilla plant) explains how it was taken to Madagascar to be grown as a cash crop by Portuguese colonisers but that it couldn’t be pollinated because the usual insect responsible for this didn’t live there. In 1841, Edmond Albius, a twelve-year-old enslaved boy living on the island of Reunion discovered how to pollinate the plant by hand. This method is still used commercially today but Edmond Albius received no financial recompense for his innovation.
Chelsea Physic Garden was one of the first places in Britain to grow Pelargoniums and the restored glasshouse now shows off the collections which originally dates from 1700s. The team were able to add new Pelargoniums to the collection, 11 of which enabled them replace specimens which had previously been in the garden and a further 17 that were new.
During our visit the team gave us a fascinating behind the scenes tour of their seedbank and seed cleaning programme. Some 42 volunteers regularly help with this process. We were also introduced to the gardens accession register, which records every plant that enters the collection and its origins.
As part of the day the garden’s volunteers were demonstrating seed cleaning and plant propagation to visitors. The garden looks after historically significant, rare and endangered plants so this programme is an important part of the work they do to continue to grow and share plant specimens.
If you are visiting the Garden Museum, then it’s useful to know that you can visit Chelsea Physic Garden as well on the same day by hopping on the 360 bus.