How a Glass Terrarium Changed the World
The Wardian case made intercontinental plant transport possible—and helped spread empires. An Object Lesson.
If you’ve ever eaten a banana, changed a car tire, or accidentally killed an orchid, then you have the Wardian case to thank. Unfortunately, you can probably also blame this small, sealed container for the rapid spread of both European colonialism and invasive plant species in the 19th century. A predecessor of the modern terrarium, it held plants, and was made of glass and closed such that it would self-regulate its internal climate.
The Wardian case facilitated the trade of plants worldwide. By allowing the transport of consumer goods like fruit and flowers, along with cash crops like coffee, sugar, and rubber, it helped shape modern, global palates and economies. It also aided in the synthesis of antimalarial quinine, which helped empires spread. The glass terrarium—an object that has become a forgettable decoration or grade-school project—changed food, botany, and commerce in the industrial era.
The case was invented by Nathaniel Bagshaw Ward, an East London doctor and amateur horticulturist. Ward’s attempts at a home garden had failed, he reported, on account of “volumes of smoke issuing from surrounding manufactories.” In 1829, he accidentally discovered a solution when he sealed a moth chrysalis and some mold in a glass jar. Moisture would rise during the day and condense on the glass, and then return to the ground when the evening cooled, “thus keeping the earth always in the same degree of humidity,” he wrote. After about a week, he could see the growth of a seedling fern and grass.
The technology Ward used was readily available, but the concept of a sealed terrarium was groundbreaking. While glasshouses were relatively common among professionals, the theory hadn’t been applied on a smaller scale. Greenhouses use solar radiation to heat the space, creating a warmer environment that is favorable to tropical plants. Both systems use similar technology and structure, but greenhouses usually require additional watering and human interference.
The Wardian case, by contrast, is an almost completely sealed environment that uses the process of condensation and evaporation to maintain humidity. The system was self-regulating, and it did not often require additional watering. London’s 1851 Great Exhibition included a Wardian case with a plant that allegedly had not been watered in 18 years.
Prevailing thought held that plants needed constant exposure to fresh air to grow during sea voyages. By sealing the box closed and using glazed windows, Ward broke with convention. This was beneficial on a sea voyage where freshwater supplies could be limited, and sailors often didn’t understand how to take care of plants. Ward’s experiment quickly earned the support of George Loddiges, owner of the Loddiges and Sons Nursery in Hackney. The foremost nursery in London, Loddiges traded plants with clients worldwide. He saw the potential in Ward’s case: A sealed means of plant transport would present valuable commercial potential.
By 1833, the pair was ready to send two Wardian cases of plants to Australia. The ship returned a year later with a load of thriving Australian specimens. “These plants were placed upon deck, and were not once watered during the whole voyage, yet on their arrival at the docks they were in the most healthy and vigorous condition,” Ward wrote.
Before the Wardian case, plant transit was principally conducted by shipping seeds. To succeed, packers needed a strong understanding of horticulture to harvest the seeds at the correct time and properly dry them. According to the historian Stuart McCook, two techniques were common for transport: covering seeds in beeswax and storing them in honey, or placing them in sealed, silk-lined tin canisters. These methods yielded low success due to pests, seed rot, and desiccation.
Previous attempts to transport germinated plants were stymied by the insistence that fresh air was necessary. Plants often died on these journeys due to vermin, extreme temperature changes, saltwater spray, and sun exposure. In 1770, the naturalist John Ellis recommended using a small box with wire coverings to prevent rats from climbing inside, and as late as 1819 the botanist John Livingstone recommended sending a gardener with every shipment. The ships attempting to transport these doomed goods were nicknamed “floating gardens”; the high failure rate forced the crews to carry many extra plants as backup.
The Wardian case brought an end to the floating gardens. As Loddiges wrote of the invention in 1842, “whereas we used to lose 19 out of 20 cases during the voyage, 19 out of 20 is now the average that survive.”
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After the successful Australian journey, Ward’s writings on the case were published and discussed with excitement within the biological-research community. A Scottish botanist named A.A. Maconochie had created a similar terrarium almost a decade earlier, but his failure to publish meant that Ward received credit as the sole inventor. The use of Wardian cases quickly spread among professional traders and amateur horticulturalists.
The successful ecological transports spurred interest among the general population, too. Although Ward wrote about the case’s potential improvements for the impoverished, it was ultimately middle-class homes that rushed to add a Wardian case to their drawing room as a decorative object that invoked Eden in the face of England’s dawning industrial revolution. Victorians, notoriously intent on controlling nature, were beset by a fern craze. The case also caused a horticultural boom, as ships arrived with new varieties of orchids and planting beds. Knowledge of Ward’s work became so ubiquitous that in 1842 Alfred Tennyson even referenced the “crystal cases” in his poem “Amphion.”
The case also transformed the diets of all social classes by facilitating the transport of fruits that are common today. A Wardian case carried the banana to Chatsworth, England, where the Cavendish banana was developed and shipped abroad in 1838. Today the large, seedless variety is virtually the only kind available in grocery stores. A Wardian case was used to bring mango grafts to Australia, and it facilitated the import of tropical fruit varieties for European greenhouse development and colonial planting. By lowering shipping-mortality rates, the Wardian case helped shape modern expectations for the year-round availability of fruit.
The Wardian case also helped bring about the end of China’s tea monopoly. Great Britain had been growing opium in India since 1757, which it then traded to China in exchange for tea. The tea trade accounted for a 10th of the empire’s gross product, which translated to important taxes for the nation. After the Opium Wars, however, the British feared that China would legalize opium production in retaliation, and quickly moved to balance the equation by introducing tea into the Himalayas.
Robert Fortune, a former curator at Chelsea Physic Garden, secretly set out with the East India Company in 1848 to gather tea plants out of China. This task had previously been viewed as impossible because of the small number of seeds able to survive the journey, but the Wardian case offered a chance for success. Fortune’s first trip failed miserably, but the following year he successfully transported some 13,000 plants from Shanghai to Assam. This spurred the growth of the Indian tea trade and broke China’s monopoly over the product. Once a luxury good, tea became available at cheaper prices for general consumption. In 1858, Fortune would use Wardian cases to smuggle Chinese tea to the United States just before the Civil War.
The vulcanization of rubber in the mid-19th century helped facilitate the spread of bicycles, and later automobiles. However, Brazil held a monopoly over rubber production in South America. The Wardian case allowed the English to secure their own rubber crop in the 1870s when Henry Wickham purchased hevea seeds at the bargain price of £10 per 10,000 seeds. Seventy thousand rubber-tree seeds were shipped from Brazil to London, germinated in Kew Gardens, and then shipped via Wardian case to Ceylon. Rubber plantations in Asia were soon more efficient and cost-effective than tapping trees in the Amazon. This diversified global production and helped create access to materials vital for the development of modern travel, but in the process destroyed the Brazilian rubber industry.
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Shipping cash crops and breaking agricultural monopolies had enormous influence, but arguably the Wardian case’s most significant contribution to European colonialism came with the spread of malaria-fighting cinchona. Cinchona bark contains quinine, an alkaloid that kills malaria parasites. Quinine was originally dissolved in tonic water for preventative consumption (reportedly, British colonials began adding gin to hide the bitter, medicinal taste). At the time, malaria served to limit Europeans’ ability to physically colonize within tropical zones.
In 1860 Clements Markham used Wardian cases to smuggle the cinchona plant out of South America. By 1861, cinchona crops were planted in India for distillation into quinine on a large scale, and spread to the Dutch across Southeast Asia. Cinchona production was essential to imperial growth. “Without it,” the historian Daniel R. Headrick insists, “European colonialism would have been almost impossible in Africa, and much costlier elsewhere in the tropics.” The Wardian case emboldened European powers to continue global expansion. And once those colonies were established, the Wardian case was also deployed to carry goods like spices and coffee to support the new territories.
Adaptation of the Wardian case was not entirely smooth. Popularity in the domestic sphere revealed tension between amateur gardeners and professional horticulturalists. The director of Kew Gardens, Joseph Hooker, criticized the case’s failures, which occurred when packed incorrectly. “I now call Ward’s cases ‘Ward’s coffins!’” Hooker lamented. Despite those reservations, Kew Gardens deployed Wardian cases up until 1962, when shorter shipping routes and the widespread use of plastic became the primary means of plant transport.
Today, the Wardian case is most commonly seen in its decorative successor, the modern terrarium. That simple ornament betrays the massive impact of Ward’s invention. Queen Elizabeth might only eat seasonal produce, but most contemporary diets can trace their roots back to the Wardian case. The case helped make tea affordable, created rubber plantations that would support Henry Ford’s Model T, and globalized botany. Remember that next time you kill an orchid.