Mushrooms in disused railway tunnels and strawberries in drainpipes... perhaps it's silly but I find food growing in strange places both bizarre and romantic. Horticulture can be so creative. It can involve melons growing on net curtains and rice growing on pavements. Introduce an against-the-odds element - like doing it in Tokyo, that seething, steely metropolis - and it's somehow all the more exciting.
My love of the bizarre and the romantic - and of vegetables - has led me on a journey, albeit it an armchair one. I've found people growing food in some unlikely places, for fun and from necessity, and on a personal and a commercial scale.
Rowena and Philip Mansfield farm fruit, herbs and fish in Anglesey, North Wales. I was drawn to this Welsh couple, who have swapped urban life for something very rural, because they've been growing strawberries in a drainpipe.
From sections of humble pipe, and employing less humble hydroponics, they've harvested 75lb of berries. They're dismissive of my delight. 'Nothing original about drainpipes,' says Philip. 'We look at all pipes and see them sprouting food. Just pass water along the tube and let the plant roots touch the liquid - they'll take up whatever nutrients they need.'
The couple have branched out into aquaponics and now sell rainbow trout and carp to a small but committed circle of customers. Aquaponics is an integrated system that centres around the natural life cycle of a fish. Philip explains: 'Fish produce ammonia in their normal breathing, the ammonia is converted by bacteria in growbeds to produce nitrates that feed the plants. The returned water has been cleansed ready for the fish to utilise it again.
'I think we should all be aware of the need to grow food by whatever means. There are thousands of empty buildings that could be used to grow food to feed the local community.'
I ask them whether it would be fair to call their way of life idyllic. 'Absolutely. The hours are long, the money scarce, but there's no travelling, no crowds on buses or Tube. You learn to live alongside nature and it rewards you generously. We breathe the growing grass.'
Grown in darkness
From old Wales to New South Wales then, to talk to an Australian microbiologist who has been growing exotic fungi in disused railway tunnels for more than 20 years. I send Dr Noel Arrold some questions by email. He isn't a fan of typing so sends me photographs of his handwritten notes in reply. They're a joy to decipher.
It turns out that Australians have been growing mushrooms in this way since the 1930s, when old railway tunnels around Sydney Harbour were used to produce them for canning. Faced with a flood of cheap canned mushrooms from Asia, the industry turned towards fresh market production and the tunnels fell out of use. But in 1987 Dr Arrold realised tunnels would be a perfect place to grow exotic fungi.
'Varieties like shiitake, oyster, wood ear and enoki grow naturally in the cool, dim and humid forests of Asia. Cultivators had developed ways of growing these mushrooms on sawdust. I discovered it was possible to grow them on Australian eucalyptus sawdust, while the tunnel environment resembled conditions that occur in the forests,' explains Dr Arrold.
'Our farm produces approximately 1,500kg of mushrooms a week, small compared to white button mushroom farms, which produce 20 tonnes a week. But ours is a high-value crop. Exotic mushrooms are attractive because the production process is chemical-free, low-energy and uses waste material.'
From Asian exotica in Australia to Tokyo, which I'm surprised to find is full of plant life. Jared Braiterman of the Tokyo University of Agriculture tells me my surprise is misplaced. 'In Edo Tokyo (from 1603 to 1868), samurai had large vegetable gardens to feed their families and to supplement their incomes,' he reveals. 'The idea that food cannot come from the city is relatively recent and inaccurate. Most foreigners think of Tokyo as a vast concrete jungle. Yet it is small-scale gardening that makes Tokyo such a welcoming place to live.'
Jared tells me about a gardener who is growing a curtain of bitter melons outside his house. 'Bitter melon - a prickly green vegetable that tastes great with ground pork - is easily grown on vertical nets. It's a way to grow food when you don't have a yard, and a way to shade sunny windows in the heat of the summer.' He also tells me that people grow rice on the pavement in old Styrofoam containers.
'In the past, city and nature were considered separate spheres. Now a very urbanised world is looking to erase those boundaries. And Tokyo provides lots of great inspiration. I think growing a single cucumber can change how people relate to nature and food. Self-sufficiency is less a goal than raising awareness.'
Mopping it up
To Africa next, where self-sufficiency is the primary goal. The UN's Food and Agriculture Organization has been collaborating with the Senegalese government to start community gardens in Dakar and neighbouring Pikine. The project encourages people to grow food in yards, on roofs and in other vacant places. They say more than 4,000 residents have started micro-gardens that produce 30kg of vegetables per square metre every year - enough to feed a family, with some left over to sell. It's an example of inventive urban agriculture that's changing lives, pulling families out of poverty and improving access to healthy food.
Back in London, architect Andre Viljoen worries about my interest in the odd when it comes to urban food-growing: 'My concern about focusing on the quirky is that the whole concept is dismissed as irrelevant, or small projects become tokens, effectively greenwash.' I wanted to talk to Andre because of a book of his: Continuous Productive Urban Landscapes, a design concept that proposes the integration of urban agriculture into cities.
'There are several different types of urban agriculture, and these should be distinguished. In the UK it is too often only associated with allotments. At one end of the scale we have small, individual and perhaps quirky growing. At the other end we have large-scale commercially viable market gardens, and these will be essential if urban agriculture is to have a significant and measurable impact.'
I appreciate Andre's concern. We need to take large-scale urban agriculture projects seriously if cities are to become sustainable, but I still can't help being charmed when some fellow Londoners tell me about their recent, minor growing exploits. One has turned a sunny parking bay into a vegetable plot, while another has been sprouting seeds on an old mop head. Surely growing can be serious and fun, and surely both things are important.
Helen Babbs is a freelance journalist
• Strawberries in drainpipes (c) Rowena and Philip Mansfield
• The mushroom tunnel in New South Wales, Australia (c) Noel Arrold
• Oyster mushrooms growing in an old railway tunnel (c) Noel Arrold
• Bitter melon curtain in Tokyo, Japan (c) Jared Braiterman
• Styrofoam rice in Tokyo, Japan (c) Jared Braiterman
• Seeds sprouting on an old mop head (c) Hedvig Murray
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