The Realities of Vertical Farming

For a start I've yet to find a hydroponically-grown item that compares in quality to the equivalent food grown in good, old fashioned soil. Take the supermarket tomato, a prime example of an everyday staple grown in nutrient solution. In flavour and succulence it can't hold a candle to the ones I produce from grow-bags in my greenhouse.

Perhaps the answer lies in greening the cities – not in a vertical direction – but on the horizontal? This is pretty much what Cuba did when the flow of Soviet oil dried up and large-scale mechanised agriculture became impossible. Under the US trade embargo the people faced starvation. The result was a proliferation of small-scale organic farms that basically kept the nation fed.

There's no reason why conurbations like London and New York shouldn't be filled with city farms in the same way as Havana. There are thousands of small areas from rooftops to urban parks that could be converted to food production. In fact it's already started to happen. Last year Harrods announced that it would be growing a range of crops – including lettuces, broad beans and tomatoes – right there on its roof.

Alternatively there's a good case for converting "green belt" land around our cities for the production of vegetables and fruit for local people. Back in the 19th century London and other cities were ringed with market gardens supplying fresh foods for the local urban population. They maintained the fertility of their soils by collecting manure from the millions of horses that were then stabled in cities.

Renewed interest in the vertical farm is a useful reminder that shorter food supply lines would bring many benefits. There's also much to be said for recycling organic nutrients including those we waste through the sewage system. But it's probably a little early to start talking up the high-rise farm.