Legal high

CANNABOOST plant food is one of the best selling products at the Hydroexpress hydroponics store in Stirchley, a working-class part of Birmingham. The small shop, its windows filled with graffiti-style posters, also sells fertilisers with names like “Nirvana” and “Bud Candy”, alongside strong lights and giant rolls of tin foil to line greenhouses. In one corner, a couple of juicy-looking tomato plants grow in a demonstration set-up. But the youth behind the counter guesses that his customers are “not all growing tomatoes”.

Birmingham now has 58 hydroponics shops, up from 42 just a year ago. Whether aided by the latest plant-growing technology or not, cannabis production is soaring. According to the Association of Chief Police Officers, the number of cannabis factories detected each year increased from around 800 in 2004 to 7,000 in 2010. Birmingham is one of the most fertile areas; West Midlands Police, which set up a Cannabis Disposal Unit in 2010 to tackle the problem, dismantled more than 500 factories last year.