Greenhouse Effect

Protected from winter’s extremes, citrus trees, palms, jasmine, and aloe thrived at Mount Vernon

One August day in Bermuda in 1784, George Augustine Washington took up his pen and wrote a letter to his namesake and uncle, General George Washington, describing his travel plans. Before he mailed it, he added in a postscript, “If you wish a supply of Orange, Lemmon & Lime Trees for your Green-House, I will procure what ever you wish and bring them with me.”

Washington’s decision to build himself a greenhouse in the mid-1780s speaks to his aspirational vision of Mount Vernon. While Virginia summers were warm enough to grow orange, lemon, and lime trees, winter temperatures could drop far enough below freezing to kill them. Chesapeake gardeners who wished to keep citrus trees needed to plant them in tubs to allow for moving indoors when the days shortened, ensuring they received enough warmth and sunlight to keep them healthy until they could be moved back outside in the spring. English landowners had begun to construct structures especially for this purpose, designated “orangeries,” in the 16th century. By Washington’s day, such buildings had evolved into hothouses with designated stoves—fired by wood, coal, or peat—that would conduct heat through a system of chimneys and flues through the floors or walls of the building. Only the wealthy could afford this extravagance, but the results were spectacular: year-round fruits and flowers, including exotic palm trees and pineapples, a short walk from one’s dining room. From Washington’s account books, we know that he ordered lemons, limes, and oranges from Caribbean merchants and candied citrus peel from London sellers. In the 1780s, home from wartime service, he wanted to grow these fruits for his table at Mount Vernon.

While greenhouses were not unknown in 17th- and 18th-century British America, they were unusual, possessed by members of the elite such as Virginia’s colonial governor, Sir William Berkeley, and the wealthy Boston merchant Andrew Faneuil. One of the loveliest was at Charles and Margaret Tilghman Carroll’s Mount Clare estate in Maryland. Washington certainly knew about this greenhouse, for he wrote to his aide and friend, Tench Tilghman, Margaret’s kinsman, with a long list of questions about greenhouse design for Tilghman to ask her. Working from Washington’s own design, the information supplied by gardening manuals, and Margaret Carroll’s advice, Washington’s enslaved laborers constructed a greenhouse that could compare favorably to any in the new United States—though it did lack the showpiece of Mount Clare’s greenhouse, a specialized hotbed for growing pineapples.

The assistance of the Carrolls proved a further boon when Margaret sent a large shipment of orange, lemon, and lime trees to stock the new greenhouse, which was completed in 1787. By the late 1790s, the greenhouse contained many plants sent as gifts to Washington or purchased by him from William Bartram’s Philadelphia nursery. In addition to citrus trees, there were palms, jasmines, aloes, and many others, and most visitors reveled in the sight, though architect Benjamin Latrobe, familiar with the great botanical gardens of Europe, sniffed that the collection contained “nothing very rare.” In some ways, the purpose of the greenhouse was simply to exist, gracing the upper garden with its elegant façade and impressing guests as a sign of Washington’s refined taste. For the men and women responsible for preparing the Washington family’s meals, however, the main use of the greenhouse was as a source of citrus to be used in recipes ranging from sweet to savory.

Martha Washington’s manuscript cookbook, passed down through the women in her family, contains many recipes involving oranges and lemons. These were not the large juicy navels seen in supermarkets today. The most common varieties were bitter oranges, Citrus aurantium, sometimes called Seville oranges. Sevilles were used like lemons to brighten flavors by adding sourness. A sweeter orange, Citrus sinensis, was known as the “China orange.” Recipes often didn’t specify which variety was required, perhaps because cooks may have had to make do with whatever was available, or perhaps as a recognition of the preferences of different cooks. Oranges and lemons garnished meat dishes, as in the stuffing recipe for a leg of lamb in Martha Washington’s cookbook. Mixed with enough sugar, citrus flavored fruitcakes, puddings, candies, or preserves; the cookbook includes recipes for all of these. Other recipes from this period, such as the ones in Hannah Glasse’s The Art of Cookery, similarly suggest that cooks use lemons in a sauce for poultry or in tarts. Eighteenth-century individuals also consumed citrus medicinally, boiling it into cough remedies, sucking on the pieces to settle the stomach, or using it as a treatment for scurvy.

Washington’s greenhouse burned down in 1835. The one visitors see today (pictured above) is a reconstruction, completed in 1952, based on a study of archival and archaeological evidence. While the original bricks had long disappeared, the rebuilt greenhouse utilizes bricks authentic to the period—notably sourced from the White House as it was being remodeled. The project was the most ambitious reconstruction undertaken by the Mount Vernon Ladies’ Association up to that point, marking a new era in the effort to restore Mount Vernon to its 1799 state. Today, as in Washington’s time, the greenhouse is one of the highlights of the upper garden