Police are urging Canberrans to be on the lookout for homes cultivating an illegal amount of cannabis plants after their teams shut down more than a dozen "grow houses" in recent years.
Although adults in the ACT have been able to legally grow cannabis plants at their home since 2020, it is a crime to grow more than two plants per person or if plants are not grown naturally (with the help of hydroponics or artificial light/heat).
ACT Policing says its Drugs and Organised Crime Team identified and tore down more than 14 grow houses, seizing and destroying more than 2600 cannabis plants, in the past three years.
The team, which works closely with the Monaro and Hume local police districts, set up "Operation Margate" in 2023 to target Vietnamese organised crime syndicates operating in the capital.
In the operation's latest update, police say six people have been arrested and charged with commercial cultivation of cannabis, one person was arrested in Canberra before allegedly being called on by Victoria Police for similar offences, while another offender was deported by the Australian Border Force.
As of June 16, four grow houses - real estate worth about $5 million - remain subject to legal proceedings and could be forfeited to the criminal assets confiscation fund.
"Police are concerned about the presence of grow houses in the ACT," a spokeswoman said.
"Grow houses require a lot of electricity and most offenders do their own electrical work to draw extra power from the grid without notice. This put themselves and others at risk."
A 36-year-old Kaleen homeowner was jailed last year after police found a sophisticated set-up and 156 cannabis plants inside his property in January 2025.
The most recent grow house bust occured in May 2025, when police suspected a Vietnamese national was responsible for more than 190 plants discovered at a house in Bonner.
An ACT Policing spokesman said no one had been arrested or charged in the Bonner case.
Describing grow houses as "highly sophisticated set-ups", police believe big criminal gangs are often behind such activities, sometimes using profits to fund other drug operations.
According to the Drug and Organised Crime Team, all grow houses require at least one person to establish and maintain the crop.
These crop-sitters are usually paid by organised crime groups who tend to select rental properties for grow houses and hydroponic set-ups that come with significant risks.
Signs of a grow house property include:
In the ACT there is no "specific offence" for setting up a grow house, a police spokeswoman said.
It's possible police discover a grow house due to a suspicious person report, a welfare check, or even a fire, she said.
"Grow houses may also be identified as part of police enquiries undertaken by general duties or other investigative areas," the police spokeswoman said.
"Not every grow house results in an offender being charged, and one person can be charged with multiple offences related to the cultivation of cannabis."
Since 2015, ACT Policing data shows the number of charges related to "drug cultivation/manufacturing" each year ranged between four and almost 50.
Police did not have records reflecting the exact number of grow houses uncovered before Operation Margate, however, The Canberra Times reports of previous police busts indicate grow houses have continued to operate in the capital over the past decade.
In 2015, police said they seized more than 1200 cannabis plants from eight rental properties with the largest discovered in Kaleen after ActewAGL reports indicated electricity was being diverted at the address.
"Never before in ACT Policing history has there been this many grow houses identified in such a short space of time that have all obviously been linked to the one organised crime syndicate," then Detective Sergeant Richard Gough said.
At the time, an unsuspecting neighbour said he was very surprised the property turned out to be a grow house and thought it might have been a university share house.
Meanwhile, between 2016 and 2019, ACT Policing said they dismantled 11 grow houses
More than 200 plants were discovered at a Kaleen address in 2020, and more than 135 cannabis plants were seized from a Dunlop house in 2021.
In December 2021, Thanh Tung Bui, 35, and Le Duong Tran, 34, were arrested at a MacGregor house after police raided the site and allegedly found 255 cannabis plants inside.
Any suspicious or illegal activity can be anonymously reported to Crime Stoppers on 1800 333 000.
