A Renaissance in GLASS HOUSES

Bringing the Scents & Sense of the Garden Indoors

Contemporary cold-climate gardeners have cucumbers —or, more accurately, Cucumis melo, melons that resembled cucumbers —to thank for the invention of the original glass house.

Tiberius Caesar, Rome’s second emperor from 14 to 37 AD, insisted his favorite fruit be available year-round, despite inhospitable winter weather. The emperor’s gardeners clothed cold frames with mica to capture sunlight—creating the firstknown ancestors of the beautiful glass structures that are enjoying a renaissance in gardens today.


“The conservatory today is an oasis of tranquility where climate and space is suited to raise — or conserve —tropical ferns, palms, cacti and mango, to cultivate rare and exquisite orchids, or to indulge a passion for dahlias and other hobby plants,” says Johnny Mobasher, CEO of Hartley Botanic, Inc., a British designer of botanical glasshouses with an office in Woburn, Mass.

The design of glass houses evolved over the centuries, following trends in both architecture and food. The popularity of citrus in Northern Europe drove the creation of the orangery to protect oranges and other citrus fruits. Indigenous to the tropics, China, and Japan, oranges were believed to have medicinal properties, and were romanticized in poetry and in Greek mythology.

The earliest-known orangeries were built in Italy during the 16th century, and coincided with the establishment of the first European botanical gardens. England’s first orangery was erected in approximately 1580 in the gardens of Sir Francis Carew in Beddington to grow citrus from seed, and remained a fixture for the wealthy throughout Europe until the mid-19th century, when Sir Joseph Paxton emerged as the world’s greatest architect of glass houses.

Above: Conservatory in the Reynolds mansion on Sapelo Island, Ga. | Below: An elegant, Victorian-era glass house is perfect for starting seeds. Photo courtesy of Hartley Botanic. “Any discussion of glass house design from 1830 onwards leads inevitably to Chatsworth, to Joseph Paxton, and to his employer, the 6th Duke of Devonshire,” writes May Woods in the book, Glass Houses: A History of Greenhouses, Orangeries and Conservatories, London: Arum Press, 1988. Paxton built the Great Conservatory, the largest glass building in the world at the time, at Chatsworth House in England between 1836 and 1841 to house the Duke’s burgeoning collection of “exoticks,” tropical plants as well as citrus, writes Woods. It covered three-quarters of an acre, and inspired the construction of conservatories worldwide, including a later Paxton masterpiece, the Crystal Palace. Erected in only 22 weeks, and spanning 19 acres, England’s Crystal Palace became, in 1851, the largest enclosed space on earth.

The Crystal Palace set a new standard for glass structures, and inspired the proliferation of conservatories as an architectural art form until World War I temporarily halted construction due to a shortage of coal and manpower to keep the buildings operating. Today, glass is the material of choice for many architects, and with good reason. A new wave of technology, including double and triple-glazing and solar glass, makes glass houses more accessible and significantly less expensive than their historical ancestors. Modern glass houses may be free-standing botanical structures, or decorative glass enclosures attached to a home.

Hartley Botanic conservatories, for example, are primarily free-standing, Victorian-era replicas of glass houses designed to over-winter plants, and adorned with cast-iron brackets, palmettes and fleur-de-lys.

Unlike sunroom kits found in big-box stores or online, bespoke Hartley glass houses are crafted in England and imported to the United States; each is constructed to fit the style of a gardener’s home. Other manufacturers of glasshouses bring the feel of the garden, versus the garden itself, indoors.

Sunspace Design, Inc., for example, is a Massachusetts-based company specializing in the design and installation of conservatories, glass enclosures, orangeries, and sunrooms attached to the home.

Sunspace not only fabricates glass houses in its shop in northern Massachusetts, it works with architects and homeowners by providing CAD (computer-assisted-design) drawings and details to aid in the final design of glass enclosures.

Technology has also helped reduce costs and promote energy efficiency in heating today’s glass houses thanks to thermal breaks to reduce heat loss, innovative radiant heating systems, and environmentally friendly eco-tubes, which generate their own bio-heat. Top: A Victorian-inspired villa. Middle: A conservatory can be ideal for tending tropical flora. Photos courtesy of Hartley Botanic. Bottom:A custom sunroom brings the warmth of the garden indoors.

Photo courtesy of Sunspace Design, Inc. “How one heats a free-standing glass house,” says Mobasher, “depends entirely upon the homeowner, and the plants grown or overwintered.” Glass houses attached to homes may be heated in the same fashion as the home, or the thermostat simply lowered to protect tender plants.

Free-standing glass houses that maintain plants over winter, by contrast, are variably heated with hot water systems, cast iron, wall-mounted, or under-floor heating systems, or small electric or gas heaters.

Warm-weather gardeners may close and empty a free-standing glass house for winter, says Mobasher, while year-round gardeners may heat the house in order to conserve plants or sow seeds for spring planting. Regardless of style, glass houses enable lovers of nature to enjoy the feel of the garden year-round. After all, who does not long for the warmth of the sun during the darkest days of January, or dream of the tropics in the midst of a frigid February?

Glass houses may do nothing to end a long winter, but, as was the case in Europe throughout history, they bring the scents and sense of the outdoors in, despite the weather. GLASS HOUSE TERMINOLOGY Greenhouses emerged in ancient Rome, and exist today, primarily as places to grow plants — often from seed—regardless of climate. | Orangeries were designed as grand architectural structures to cultivate citrus plants for the wealthy in cold climates.

Conservatories were erected historically on the land of the wealthy to protect tender plants from cold weather, including, but not limited to, citrus. Modern conservatories may comprise grand structures attached to an estate, free-standing Victorian glass houses in a small garden, or any glass room that houses plants during winter. Views from within: These botanical conservatories connect the indoors to the outdoors, providing quiet places to read, to grow exotic plants, or to entertain. Bottom photo courtesy of Hartley Botanic.