Home-grown cannabis is a booming business

Three cannabis farms are shut down every day, but police are struggling to keep pace with the boom in home-grown production of the drug. More than 60 per cent of the marijuana now smoked in Britain is cultivated in this country, compared with just 11 per cent a decade ago. The plant is grown everywhere from inner-city lofts to secluded patches of farmland.

An investigation by the charity DrugScope has found that growing cannabis is a big business in Britain and that Vietnamese gangs have a stranglehold on the illicit trade.

Over the past six months, cannabis farms have been raided at the rate of three a day. More than 1,500 have been discovered in London alone in the past two years, three times as many as in the previous two years.

Police have tended to focus on the production of "skunk", one of the most potent forms of cannabis, containing higher than average quantities of the potentially dangerous chemical THC. The research also belies the old image of cannabis users growing a handful of plants on their windowsill, with police saying they are recovering an average of 400 plants per raid.

The problem for police is that growers only need lights, fans and plant pots to set up in business. Baths are commonly used as nurseries, with plants also crammed into attics, cellars, bathrooms and summer-houses.

Gangs are also renting units on industrial estates in an effort to disguise the large amounts of electricity needed for marijuana cultivation. Police, who often use hand-held or helicopter-mounted heat-seeking devices to detect illicit crops, found cannabis farm where the lights were wired up to the street lights outside. Another tactic is to sow seeds on other people's land and to return three months later to harvest it.

Many of the gangs opt for fast-growing plants rather than skunk because of the rapid profits they can produce.

DrugScope reports that between two-thirds and three-quarters of the farms raided by police - ranging from south Wales to the North-east - were run by Vietnamese gangs.

Many growers, some of whom are as young as 15, are illegal immigrants forced by the gangs which smuggled them into the country to live in cramped conditions. Police found them living in cupboards, tiny utility rooms and lofts, in order to maximise the space for plants.

Fifty cannabis farms were discovered in London last year following house fires caused by faulty lights or wiring.

Harry Shapiro, director of communications at DrugScope, said: "Growing cannabis commercially near the point of sale can dramatically increase profits, but this increases the risk of detection. There are significant implications for police resources in trying to keep up with the growers, who are becoming increasingly smart in establishing new farms and avoiding arrest."

DrugScope said the surge in cannabis growth in Britain has filled the gap left by the disillusionment of users with the quality of imported cannabis resin. The amount of the drug produced in Morocco, previously a prime source of the UK's supply, has almost halved following an eradication scheme.

More than three million Britons are believed to use cannabis regularly, a higher proportion than elsewhere in Europe.

It typically costs £30 to £80 per ounce of resin, £35 to £110 for herbal cannabis, rising to £160 for marijuana of the highest quality.

Recent drugs raids

* 8 FEBRUARY Police uncover 250 to 300 small cannabis plants in a barn at Devauden, Gwent.

* 23 FEBRUARY Manchester police arrest eight people and seize hundreds of plants in raids on three addresses in Chorlton.

* 27 FEBRUARY More than 200 plants are discovered by police making a routine inquiry at a home in Leeds. They investigated after smelling cannabis.

* 3 MARCH About 200 plants worth £44,000 seized at a house in Chatham, Kent. In the past five months 20 nearby farms have been shut down.

* 5 MARCH Police find about 1,000 plants, worth about £200,000, at a home in Forfar, Angus.

* 6 MARCH The landlord of a Bolton property finds hundreds of plants after the electricity supply to an adjoining property fails.