Is it illegal to grow cannabis in the UK?

Cannabis is a Class B controlled drug under Schedule 2 of the Misuse of Drugs Act 1971. Section 6 of the Act makes it an offence to cultivate any plant of the genus Cannabis. There is no distinction in law between growing one plant for personal use and cultivating on a commercial scale: both are criminal offences.

The maximum penalty for cultivation of cannabis is 14 years' imprisonment on indictment, or 6 months and/or an unlimited fine on summary conviction. In practice, sentences vary enormously depending on the scale of the operation.

The Sentencing Council guideline for cannabis cultivation distinguishes between four categories: Category 1 (very large-scale commercial), Category 2 (significant commercial), Category 3 (lesser role or smaller scale), and Category 4 (very small scale, personal use). For a single plant grown for personal use, a conditional discharge or small fine is a realistic outcome. For a commercial grow operation, custodial sentences of several years are common.

The offence of cultivation is distinct from possession (s.5) and production (s.4). Production carries the same maximum penalty but is typically charged for more industrial-scale operations. Possession of cannabis carries a maximum of 5 years' imprisonment on indictment.

Police regularly discover cannabis grows through intelligence, reports of unusual electricity consumption, heat signatures, and the distinctive smell. Under s.23 of the Misuse of Drugs Act 1971, police can enter and search premises with a warrant issued by a magistrate if there are reasonable grounds to suspect controlled drugs are being produced.

The legal position in England and Wales has not changed despite legalisation in some other jurisdictions. Cannabis remains illegal to cultivate, possess, and supply. Medical cannabis was reclassified as Schedule 2 in November 2018, allowing specialist doctors to prescribe it, but this does not affect the general prohibition on cultivation.