Fruit Walls Urban Farming in the 1600s

FROM THE 16TH TO THE 20TH CENTURY, urban farmers in Europe grew Mediterranean fruits and vegetables as far north as England and the Netherlands. They grew these crops by planting them next to massive “fruit walls,” which stored the heat from the sun and released it at night, creating a microclimate that could increase the temperature near the walls by up to 22 degrees Fahrenheit as compared to the surrounding area. Later, greenhouses built against the fruit walls further improved yields by capturing and storing energy from the sun even more effectively.

It was only at the very end of the 19th century that the greenhouse turned into a fully glazed and artificially heated building. Modern glass greenhouses require massive inputs of energy for heating, especially because they’re often located in temperate climates with cold winters, plus many require artificial lighting and humidity control. Heating a building that’s entirely made of glass is very energy-intensive because glass has a limited insulation value.