California has long been seen as the stoner capital of the United States, but the largest state has finally joined seven other states and the District of Columbia to legalise the recreational use of the drug.

Marijuana became legal in California from Monday and users can now grow  plants and buy legal cannabis products.

Medical marijuana has been legal in California since 1996 and the pot industry has since become big business – even before Hollywood movies like The Big Lebowski and Pineapple Express took stoner humour to the mainstream.

With the legalisation of recreational marijuana the market is expected to increase to $US3.7 billion this year ($4.74 billion) and to over $US5 billion in 2019, according to the Business Insider.

The new California law, passed by voter referendum in 2016, allows people over 21 to possess, transport, purchase, consume or share up to 28.5 grams of marijuana, and up to eight grams of marijuana concentrates.

Adults can grow up to six plants per household “out of public view.”

However, the two largest cities in the state – Los Angeles and San Francisco –have not yet started issuing licences to sell cannabis commercially for recreational use.

Los Angeles city officials say they plan to start the process of issuing licences for the sale of recreational marijuana on Wednesday.

The city “just ran out of time” to get the necessary regulations in place, explained Adam Spiker, executive director of the Southern California Coalition, a marijuana industry group.

Marijuana remains illegal under federal law.

-AAP