Cannabis farms: the dangers and tell-tale signs for landlords Cannabis farms: the dangers and tell-tale signs for landlords

Cannabis farms: the dangers and tell-tale signs for landlords

It's reported that 94% of cannabis farms (also known as factories or grows) are located in domestic premises.

With over 2.1 million adults admitting to having used cannabis in 2020, and 10 million saying to have tried it at least once in their life, it's no surprise that it's the most commonly used illegal drug in the UK.

Since the early 2000's, there's been a steady rise in cannabis farming taking place in smaller, residential properties. Cannabis cultivators are more likely to use a house than a flat, as they need the space, and they tend to choose secluded properties in areas where there is little through-traffic, such as cul-de-sacs.

The rise of farming taking place in domestic households is alarming for private landlords and letting agents, especially when considering that there are currently more people renting from private landlords than council and housing association homes. So private landlords need to learn the tell-tale signs of cannabis farming early on in order to make an impact.

Read our landlord's guide of dos and don'ts when it comes to choosing your tenants.

What is cannabis farming?

To put it simply, cannabis farming is when an organised crime gang uses a domestic property to illegally grow cannabis in bulk. It's a big business across the UK and not only does it likely damage your property, but it also invites the potential use of violence.

The size of a property will change the way in which it's operated. For smaller operations, an attic, garage or single room could be used for farming, however, for larger operations, whole houses may be used.

Damage and impact on landlords

Landlords who have been the victims of this type of criminal activity have reported the following types of damage to their properties:

  • Ceilings and walls knocked through and floorboards ripped out
  • Severe water damage
  • Fire and explosion
  • Furniture destroyed or thrown away
  • Wiring ripped out
  • Electricity meters bypassed

The consequences for landlords, in both financial and legal terms, can be catastrophic. In addition to the financial cost, landlords could also face prosecution themselves.

How to avoid falling victim

Steps you can take to weed out tenants who may be involved in this kind of activity:


  • Carry out in-depth tenant checks:
    • Insist on photographic identification (check it hasn’t been altered)
    • Take references from previous landlords and employers
    • Ask for recent payslips or bank statements
    • Check tenants’ current addresses
    • Look out for utility bills in different names 
    • Run a credit check with a credit reference agency
  • Be wary of tenants who take particular interest in the electricity supply 
  • Be wary of tenants who want to move in very quickly
  • Carry out regular inspections of the property
  • Communicate with the neighbours regularly
  • Take mobile numbers for all tenants
  • Get paid via the tenants bank account / BAC


  • Accept cash for rent, deposit or administration fees
  • Offer short-term lets
  • Accept any requests for you not to visit the property to make an inspection
  • Allow the property to become ‘invisible’: keep the greenery trimmed back and make sure the house number is clearly visible from the road

How to spot a cannabis farm

Here are some key warning signs that your property may be being used as a cannabis farm:

  • An unusual amount of activity when the tenants first move in
  • Paranoid behaviour by your tenants
  • A large number of visitors (day and night)
  • Excessive fortification of the property (inside and outside)
  • Silver duct tape hanging out of windows
  • Blacked out windows
  • Low-level hanging equipment
  • Humidity: condensation on windows, peeling wallpaper, mildewed walls
  • A pungent smell
  • Excessive use of deodorisers and air freshener
  • Sudden fluctuations in electricity bills
  • Electrical wiring tampered with
  • Powerful lights on day and night
  • Noise
  • The following items around the property (inside and outside):
    • Plants, lights and reflective materials
    • Bulbs, soil, fertiliser
    • Flasks, beakers, rubber tubing
    • Bubble bags
    • Scales
    • Self-seal bags
    • Gas cylinders

If you recognise some of these things and suspect your property is being used as a cannabis farm, contact your local police straight away. Do not confront your tenants yourself.

Beware of 'cuckoo-ing'

If cannabis farming wasn't a big enough issue, there is now a trend called 'cuckoo-ing'. This is when the criminals target a vulnerable existing tenant and use their home for cannabis farming. The target is usually, but not always, someone with learning disabilities, mental health conditions or a substance user.

After tricking/coercing the tenant into allowing the gang to grow or deal drugs in their house, the tenant may be forced to help, as well as forced to stay silent. As a landlord, you can look for warning signs of this by doing more regular house inspections. Under the Landlord and Tenant Act 1985, landlords have the right to enter the premises to view its “condition and state of repair”. However, too regularly and this could be deemed as harassment. You also must do so at “reasonable times of the day” and give 24 hours' written notice.

Help and advice

Although landlords are not legally responsible for the behaviour of their tenants, they do have a duty of care to make sure that their tenants don't cause problems in the wider community.

If you're suspicious of a cannabis farm, you should contact the police immediately. Due to the violent nature of some crime organisations, it's best not to get personally involved.

The information contained on this web page is for general information purposes only and does not constitute legal or other professional advice. Direct Line for Business does not accept liability for the information contained on this web page, nor does it make any representations or warranties as to the completeness, accuracy or suitability of such information.

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Last Updated: 6 May 2021