Hothouses and Pineapples
The goal of many imperial expeditions was to explore the natural resources of colonies in search of potentially profitable plants and products. Naturalists brought back seeds, fruits, whole plants, roots, or cuttings of exotic plants, hoping to grow them back in Europe. From South America, the pineapple captured the curiosity of Western visitors as early as 1493 when Christopher Columbus came across it in Guadeloupe. With its sweet fragrance, delicious taste, bizarre appearance, and medicinal digestive properties, gardeners and naturalists were keen to introduce it to European consumers.
Long-distance transport presented a problem, though. Even when picked green in the New World, pineapples rotted by the time they crossed the Atlantic, thus requiring their cultivation in Europe. In the early eighteenth century, although tropical plants like the pineapple grew in Spain and southern Europe, they were impossible to grow in northern parts of Europe, as they demanded more year-round warmth and humidity than the chilly northern winters allowed. To cultivate tropical fruit like pineapple more widely in Europe, therefore, technological developments were needed to create enclosed and consistently warm environments.
In 1720, botanist Henry Telende, gardener to Sir Matthew Decker of Surrey, repurposed tanner’s bark (oak bark) from leather working to warm hothouses. Bark stoves (also called pineapple pits or pineapple stoves) were small, glass-walled frames with holes in the ground in which pineapples were potted and surrounded by layers of horse manure and tanner’s bark. In 1675, John Evelyn had recommended forcing pits filled with dung over which trays of pineapple plants could be grown, but Telende’s addition of tanner’s bark proved invaluable. The careful mixing and maintenance of the right amount of manure and bark yielded a fermentation process that trapped heat around plants to keep them warm. A 1770 fruit cultivation guide praised tanner’s bark and the pineapple stoves of hothouses, exclaiming,
thus we are enabled, when these bark stoves are rightly contrived, to preserve the most tender exotic trees and plants, which before the use of the bark was introduced, were thought impossible to be kept in England.
Guides for growing pineapple and other tropical fruit brought back from imperial expeditions were common publications in the eighteenth century. Pineapple quickly became a status symbol as only wealthy patrons with the best gardeners could cultivate such a delicate, expensive plant that required daily upkeep year-round. Gardeners of wealthy estates competed to produce superior pineapples and varieties that others did not grow. Having a pineapple as a centerpiece for important dinner parties was so highly regarded that some shops even rented the fruits out to households by the day.
Some hothouses included not bark stoves but dry stoves in which the source of heat was not fermenting dung and tanner's bark but a network of flues or chimney pipes that transported the heat of smoking fires to the plants. By the end of the eighteenth century, however, improvements to hothouses eliminated the need for either flues or tanner’s bark altogether, altering the glass hothouse design to be heated primarily by sunlight. This predecessor of the modern greenhouse simplified the cultivation of pineapples and other tropical plants, making them more accessible to grow and purchase.
Anderson, James. A description of a patent hot-house. London: Printed for J. Cumming, 1803.
Drower, George M. F. Gardeners, Gurus & Grubs: The Stories of Garden Inventors and Innovations. Stroud: Sutton, 2001.
Garton, James. The practical gardener, and gentleman’s directory, for every month in the year. Dublin: Printed for H. Saunders, D. Chamberlaine, J. Potts, W. Sleater, and J. Williams, 1770.
Laws, Bill. Fifty Plants that Changed the Course of History. Buffalo, NY: Firefly Books, 2010.