Across a north London rooftop rows upon rows of lettuce are laid out ready to be picked, bagged and sold in the supermarket below. This is part of the ‘Food from the Sky’ project on top of Crouch End’s Budgens’ store. The rooftop garden also grows herbs, a selection of vegetables and other salad products. While the weekly harvest contributes to the amount of produce on the store’s shelves, it cannot supply all of it to meet the needs of shoppers.

This is the challenge that urban farming is up against. At the moment such projects can only supplement fresh produce purchases, but they cannot meet the total demand.

However, agricultural land is increasingly in short supply and prices are rising fast thanks to a combination of pressures, including overseas investment and changes to trust law that have encouraged many investors to look for alternative means of inheritance tax mitigation. Owners of agricultural land and forestry pay no inheritance tax, provided the land has been held for at least two years prior to death, giving it many attractive tax advantages. Increasingly, food producers are finding it hard to find land to farm, without even throwing in the weather-related problems once they do manage to sow a field.

If the UK is to avoid becoming even more reliant on food imports then we need more solutions. Ben Mann, director of short documentary Best Before, which looks at alternative food sources in London, agrees that urban farming has limitations and instead puts forward another idea. “Urban agriculture will not provide the main bulk of food needed to feed a large city, but it provides a necessary and vital educational role in raising awareness about, and connecting people to, where food comes from,” he explains. “Further, it can provide a certain amount of fresh, perishable food items such as kale, salad and herbs. This can also provide local employment, promote community events and awareness, and can ‘green’ brownfield sites and disused urban spaces. It performs a very useful role in this sense.”

Mann adds that from his research and interviews for the documentary, he believes the greatest potential for more significant volumes of local food for city dwellers comes from ‘peri-urban’ farms such as OrganicLea, in the Lea Valley. “This produces a sizeable amount of food, and though the amount of food produced in certain urban farms may be limited due to land access, there is the potential for many more, similar-sized, peri-urban farms that can deliver a greater amount of produce.

“The key point is that local food co-ops, farmers’ markets and organic vegetable boxes start from the principle of sourcing produce from as locally as possible.

“The key to changing a food system may lie more in raising awareness and garnering support from policy makers than from trying to attempt to just increase volumes of produce in city areas.”

While ‘peri-urban’ farming is one solution, the fact remains competition for land, especially for residential development, is fierce and is only going to get tougher. Organisations such as Forum for the Future and experts including Columbia University professor Dickson Despommier say that while it is not realistic to expect vast areas of brownfield land to be turned over to growing food, there are ways to maximise production.

Senior sustainability officer for Forum for the Future, Simon Billing, says the organisation has just launched a major research project into protected cropping, which are fruit and vegetables grown under glass or plastic. Billing adds that urban areas are far more likely to be receptive to protected cropping, with many rural councils facing opposition from residents to the expansion of glasshouses or polytunnels. “It’s more about public perception of food that has been grown indoors,” he says. “With such great substrates available you do not even need soil to grow food, but it’s hard for people to get away from that idea that food has to be grown in a field.”

Billing points to projects in Holland and North America of agro-industrial parks, where waste heat is repurposed for glasshouse growing and rainwater, plus grey water, is captured and used for irrigation.

Already in the north of England, one such business exists. The Teeside-based Belasis Park, opened in 2006, houses six gigantic greenhouses, producing more than 7,000 tonnes of tomatoes all year round. The £14m plant takes by-products of carbon dioxide, electricity and steam from chemical firm and fellow business park enterprise Terra Industries to aid production.

Billing says there is plenty of opportunity to expand such schemes, but it would take major investment. He adds: “There is a lot of entrepreneurism in this field but to take it to scale ultimately it needs investment. Supermarkets are always looking to distinguish themselves and this would be one way, to invest in urban farming.”

Where there is such pressure on land, the answer may come in the form of vertical farming. Despommier is a leading exponent of this concept of building food production towers. Yet, this still entails a hefty amount of investment – apart from the land, the basic cost of such a facility can start from £1.24 million, according to Despommier. The upside of the idea is that apart from grains, which are difficult but not impossible to grow, almost every vegetable or bush fruit can be grown in the towers. “How tall the towers are depends upon how much you want to spend,” says Despommier.

Given the weather problems and land issues, coupled with population growth, it is clear that urban farming can no longer be dismissed as a fad but needs serious investment to develop what could become a legitimate source of significant supplies. —

BANKING ON A BRIGHT FUTURE

The trend for urban farming has moved to new heights with Coutts, the private bank, creating a kitchen garden on the roof terrace of its London headquarters on The Strand.

In an area that was, as the bank puts it, a disused and unsightly space, there are now over 9,000 organic plants including vegetables, fruit, herbs and edible flowers growing some 30 metres above street level.

Executive chef Peter Fiori uses the produce for the private dining rooms where the bank entertains clients and investors, while horticulturist Richard Vine tends to the ‘Skyline Garden’, as Coutts calls it. Fiori says the project has far exceeded all hopes.

“Not only do we have access to the ultimate fresh produce, which is picked at exactly the optimum size, taste and texture, but there are other benefits too such as reduced air and road miles.”