Reports of marijuana cultivation are up 28 percent in the UK since authorities introduced “scratch and sniff” cards as a means of helping the public identify grow ops. The increase in cultivation reports took place over a three-month span earlier this year.

The idea to use “scratch and sniff” cards to “educate” the public about the smell of growing pot was inspired by the Dutch government, which began handing out similar cards three years ago. Earlier this month, the Netherlands implemented the program nationwide.

In the UK, the "scratch and sniff" campaign has led to more than 3500 tips from citizens and resulted in 34 pot farms being raided and shut down. Roughly £2.1 million of pot has been seized ($3,391,080)  

Over 200,000 cannabis detection cards were distributed to residents in London, Merseyside, Greater Manchester, South Yorkshire and Avon and Somerset beginning in March 2013.