Urban beekeeping has experienced an unprecedented rise in popularity in the past three years with thousands of new honeybee colonies, but there is no agreement among beekeepers on whether urban areas will be able to feed the honeybees.
Regent's Park beekeeper, Toby Mason, insists that the 489-acre London park provides ample forage for his 40 hives. In Liverpool, Doug Jones, who keeps a couple of hives on the roof of a museum in the city centre, says they do better than his hives at home in the suburbs. But the reason he gives is not an abundance of innercity forage. "Where I live there are so many beekeepers that competition is fierce and we don't get much honey," says Jones.
Research from other countries suggests bees reared in cities are more productive than their country cousins. A study by French beekeepers' association Union Nationale de l'Apiculture Française (Unaf), for example, found bees in Paris had higher honey yields and lower mortality rates than bees in the countryside. But that could say more about the poor state of intensively farmed and pesticide-ridden rural France.
Here, with two thirds of London given over to green spaces, many believe that it is unlikely we have reached bee saturation point just yet. But John Chapple, chair of the London Beekeepers' Association, is right to raise concerns about the influx of bees in our cities, potentially putting a strain on food resources. Many highly cultivated flowers that add a splash of colour to our urban environment have been selected for showy blooms that produce little or no pollen and nectar for bees.
If we are serious about halting the decline of honeybees we can't just blithely introduce beehives into urban areas without being aware of the potential consequences if there is scant forage to sustain their 50,000 inhabitants.
Pamela Brunton from the food charity Sustain, which is managing the mayor of London's Capital Bee competition to offer 50 community food growing groups to chance to keep honeybees, points out that there has been no research into how much forage different pollinators need, so it is impossible to say how many hives cities can support. "In fact, urban environments have been shown to be very good for bees because of the year-round, diverse forage available to them in our parks and gardens," she says.
The Sussex University apiculture professor Francis Ratnieks says: "I don't think that any specific recommendation can be made about the number of hives per unit area as this depends very much on the amount of flowers, and will also vary month by month."
With the loss of 97% of our flower-rich pastures since 1947 in the UK, and a fifth of heather-rich moorland in England and Wales, the question of whether towns and cities now provide richer food sources for honeybees, and if so how we better manage this urban land, has prompted a flurry of academic research. At Sussex University, they are decoding the bees' waggle dance – by which the bees communicate to each other about where to find a good source of food – in order to pinpoint where they are foraging at different times of the year. The National Pollen and Aerobiology Research Unit at the University of Worcester has been analysing samples of pollen in urban and rural hives and has found more diversity in the former because urban bees are able to visit a much wider range of flowers.
Prof Jane Memmott at the University of Bristol has received £1.2m from the Insect Pollinators Initiative (IPI) to identify hotspots of insect biodiversity in cities across the UK.
"We're divvying the cities up not just into gardens – we'll look at bits of wasteland, industrial estates, shopping malls – to ask where there are the little oases for plant pollinators. We'll ask what we can do in cities to make them more pollinator-friendly?" she explains.
"There is plenty of anecdotal evidence about cities being havens of biodiversity but no statistics, no proper science to back this up."
Her findings will provide a blueprint for towns and cities all over the UK. "The trick is to show councils that these flowers can look beautiful rather than like weeds. And if we can demonstrate that it is cheaper and better to plant longer-lasting native perennials and wildflowers than expensive short-term bedding plants then we will be able to improve biodiversity in our cities," she says.
In Newcastle, the city council has already made its horticultural services and ground maintenance bee-friendly at a neutral cost. Newcastle University's Dr Geraldine Wright, who is advising the council on its bee-friendly planting, also won a IPI grant to examine both the nutritional needs of honeybees and bumblebees and the nutritional quality of pollen and nectar. "This will allow us to estimate both whether the amount of forage in a given habitat is sufficient and also whether it is nutritionally 'complete'," explains Wright. "I agree that having more folks keeping bees in urban environments could actually lead to trouble if there isn't enough food for the bees being kept."
They plan to build a free, online database of the nutritional quality of nectar and pollen so the public can improve foraging habitat for bee species.
What can we do more immediately to help bees flourish in our backyards? Chapple advises people to plant bee-friendly trees and flowers rather than becoming a beekeeper.
Gardens contain more flowers than most agricultural land and in Britain they cover more than one million hectares. However, a lot of gardens are not especially friendly to any wildlife. Many are covered with paving or decking or are planted with exotic or highly cultivated garden flowers. But if people started to think of their backyards as mini nature reserves the future of bees and other pollinators would be a little more secure. There is plethora of information from wildlife trusts, the British Beekeepers' Association and the Bumblebee Conservation Trust about which plants and flowers will attract different bees.
Chapple also advises lobbying councils to make their parks and green spaces more bee-friendly. He says: "Stop parks from planting double-headed flowers, cutting back trees and shrubs before they flower, mowing dandelion-strewn lawns that provide vital nectar and pollen for bees and spraying with chemicals".
• This is an edited extract from Bees in the City; the urban beekeepers' handbook by Alison Benjamin and Brian McCallum, published on 4 August by Guardian Books, priced £12.99