Like George Washington, Thomas Jefferson’s interest in gardening was influenced by European trends. His gardening mentor, Bernard McMahon, an Irish nurseryman and writer, was probably instrumental in encouraging that he build his own. Because Jefferson himself had travelled extensively in Europe, he had seen many greenhouses – freestanding structures later known as orangeries, which were important features of many distinguished gardens throughout Europe.
In America, greenhouses became increasingly popular at the turn of the century, as growing prosperity made building and maintaining them more feasible. Particularly in Virginia and Philadelphia, where winters were milder than in New England, a surprising number were buil,, and some still survive. By the 1790’s, Jefferson’s trips to Philadelphia often included visits to William Hamilton’s estate, Woodlands, which sat on the banks of the Schuylkill River. Part of this garden’s allure was a greenhouse one hundred and forty feet long. He also would have visited Washington’s greenhouse at Mount Vernon during the same period.
He made at least two plans for greenhouse structures-once during the 1770’s, and again in 1805, but the plan he eventually adopted was a third one. In 1804 the construction began of a small, glass- enclosed arched loggia, which he dubbed the “South Piazza,” and which was part of the house itself. The structure was not completed until 1809.
Once built, the greenhouse was not entirely a success. In 1811, responding to an inquiry from McMahon, Jefferson replied, “My frequent and long absences at a distant possession render my efforts even for the few greenhouse plants I aim at abortive.” During my last absence in winter, every plant I had in it perished.”
By the end of his life, Jefferson’s greenhouse had become an enclosed porch and storage room. Despite regular shipments from Mr. McMahon, including many choice plants that resulted from the Lewis and Clark expedition, and the first tender South African bulbs available to American gardeners, he had given up horticultural aspirations for the space. He was neither at home enough, nor able to keep it sufficiently warm for plants to survive.
It is humbling to observe that even a founding father can fail. And an interesting object for meditation in this month of new resolutions. It’s easy to lose sight of the essential and few conditions necessary for plants to thrive under glass. Are you making the most of your greenhouse?