The earliest known greenhouse was built somewhere around 30 A.D. for the Roman Emperor Tiberius. At this time, a greenhouse was extremely difficult to build because glass had not yet been invented. This small greenhouse, called a specularium, was painstakingly fabricated from small, translucent sheets of mica.
The greenhouse was built to satisfy the emperor's craving for cucumbers out of season. The first practical greenhouse was designed by a French botanist and constructed in Holland. It was intended to grow tropical plants for medicinal purposes.As greenhouses evolved, they were called orangeries and pineries. Pineries were not made to grow pine trees but were made to grow pineapple. George Washington craved pineapples and ordered a greenhouse pinery built at Mt. Vernon so that he could serve them to his guests.
Greenhouses became more and more elaborate and were, of course, only for the extremely wealthy, because glass was considered a luxury and was highly taxed. Greenhouses are now available in all price ranges and sizes and are no longer only for the wealthy. -- Larry Sagers