The Forestiere Underground Gardens: A Subterranean Architectural Landmark

The Forestiere Underground Gardens in Fresno, California, consist of 65 subterranean rooms, courtyards, and passageways hand-carved by Baldassare Forestiere between 1906 and 1946. Listed on the National Register of Historic Places in 1977, the site serves as an unconventional example of vernacular architecture, utilizing natural cooling and light to sustain a productive orchard beneath the earth’s surface.

Origins and Construction of the Underground Space

Baldassare Forestiere, an immigrant from Sicily, began excavating the site after finding the local hardpan soil in Fresno unsuitable for citrus trees. Forestiere initially dug a small cellar to escape the summer heat. After finding the underground environment comfortable, he expanded the project over 40 years using only hand tools and a pair of mules.

The structure spans 10 acres and reaches depths of up to 23 feet. Forestiere built the complex without blueprints, creating a sophisticated environment that includes a summer bedroom, winter bedroom, kitchen, and fishpond. He reused excavated hardpan as bricks for archways and structural supports, creating a stable, self-contained habitat.

Environmental Engineering and Agriculture

The garden’s design demonstrates an intuitive grasp of thermodynamics. Forestiere constructed rooms of varying widths and utilized conical skylights to regulate airflow and temperature. The narrow passages accelerate air movement, while the skylights allow hot air to escape, keeping the lower levels cool during the summer. During the winter, the earth acts as insulation, protecting the trees from frost.

The underground orchard contains a variety of fruit, including citrus, kumquats, loquats, and jujubes. Many of these trees are over 100 years old. To maximize the harvest, Forestiere grafted different varieties onto single trees, allowing for a diverse range of produce within the subterranean chambers. By planting at different levels and times, he successfully extended the growing season, creating a functional food source that thrived in an environment typically hostile to such vegetation.

Historical Significance and Preservation

The Forestiere Underground Gardens were recognized as California Historical Landmark No. 916 in 1978. The site is currently managed by members of the Forestiere family through the Forestiere Historical Center, which maintains the grounds and provides public access to the historic structure. While the gardens remain a testament to one man’s persistence, the site has also entered the cultural consciousness; novelist T. Coraghessan Boyle published a fictionalized account of Forestiere, the short story “The Underground Gardens,” in The New Yorker in 1998.

Key Facts About the Gardens

• Total Rooms: 65 individual chambers.
• Excavation Period: 1906–1946.
• Maximum Depth: 23 feet.
• Preservation Status: Listed on the National Register of Historic Places (1977) and as a California Historical Landmark (1978).

Frequently Asked Questions

Why did Baldassare Forestiere build the gardens?
Forestiere initially sought refuge from the summer heat and found that the hardpan soil was unsuitable for citrus trees. The underground construction solved both the climate and soil problems.

Are the plants still growing today?
Yes. The gardens continue to house a variety of fruit trees, some of which are over a century old and still bear fruit due to the protected microclimate provided by the subterranean architecture.

How were the gardens built without blueprints?
Forestiere worked section by section over four decades, likely influenced by Roman catacombs and wine cellars he had seen in Italy to guide the structural design.