If you are interested in how farmers produced fruit and vegetables in the days before modern technology and greenhouses in colder climates, you will enjoy reading this article in Low-Tech magazine. It describes the use of walls to help warm up local areas by solar energy, allowing the cultivation of Mediterranean fruits and vegetables as far north as England and the Netherlands. The massive “fruit walls”, which stored the heat from the sun and released it at night, created a microclimate that could increase the temperature by more than 10°C (18°F). You can read more about how they were used and how they morphed into the modern greenhouse here.
