Today, fruit graces the breakfast table and makes an appearance at lunch and dessert. Is this a new phenomenon with worldwide trade? Surprisingly, fruit actually has been a part of urban farming since the 1600s.
So common logic, and many experts, tell us we should buy local, seasonal food, right? Produce transported hundreds or thousands of miles just doesn't have the same quality. And it makes sense. Not only has this food been transported a long distance, but it is often grown in greenhouses that suck up energy fast.
But growing produce in far-away lands and shipping long distances weren't always such an intensive process. In fact, from the 16th to the 20th century, Mediterranean produce was grown using only renewable energy as far North as England and the Netherlands.
The secret laid in the construction of massive 'fruit walls' that would store heat during the day and release it at night, raising temperatures as much as 10 degrees Celsius.
The fruit wall would face sunlight during the day and soak up solar heat, creating a microclimate. The walls would also protect the crops from northern winds. Roof times or canopies could also shield crops from rain or hail.
If it sounds a bit like a greenhouse, that's because it was a very similar concept. But unlike the modern incarnation of the greenhouse, the ancient crop-growing process known as espalier was actually very energy-friendly.
To give you a little perspective, the FAO states that crops grown in heated greenhouses demand as much as 20 times the energy needed for crops grown in open fields. From a country like the Netherlands, which produced the largest amount of greenhouse-grown crops in the world, that energy equates to half the amount of fossil fuels as used in Dutch cars.
This is largely due to the fact that every square meter of glass loses up to ten times as much heat as a traditional fruit wall.
The espalier process was perfected by Middle Age-period Europeans and was genius for its ability to save space and improve growing conditions.