Officers from Titan, the North West regional organised crime unit, will today launch Operation Broadley, a month-long effort to stem the rise of cannabis cultivation linked to organised drug gangs.
Police have uncovered 5,120 cannabis factories across the region in the last three years, containing over 345,000 plants with an estimated street value of £140 million.
The operation will see police in Greater Manchester, Merseyside, Lancashire, Cheshire, North Wales and Cumbria execute more misuse of drugs warrants against those who grow cannabis and campaign for the public to act as their "eyes and ears".
Police say tighter border controls have led dealers to grow marijuana plants in the UK rather than import it.
Cannabis cultivation offences involving 10 or more plants increased by 16% in Greater Manchester last year.
In Merseyside, there have been 1,214 people arrested on suspicion of growing cannabis in hundreds of raids in the last three years.
And in Lancashire alone, 485 cannabis farms were discovered between October 2010 and December 2011.
Operation Broadley aims to help utility companies, garden centres, DIY stores, local authorities, fire services and the Royal Mail spot signs that cannabis is being grown.
Tell-tale signs are:
- Strange smells and sounds
- Frequent and varied visitors to a property, often at unusual times
- Gardening equipment being taken into a property, such as plant pots, fertiliser, fans and industrial lighting
- Windows are sealed and covered or the curtains are permanently closed
- Heat from an adjoining property
Cannabis was reclassified from a class C to a class B drug in 2009, with dealers caught selling the drug facing up to 14 years in prison.
Possession can lead to anything from an £80 on-the-spot fine up to five years imprisonment.
Anyone with any information about cannabis cultivation is asked to call Crimestoppers anonymously on 0800 555 111