Ruderalis

Cannabis ruderalis is a botanical classification of a subspecies of cannabis plants alongside indica and sativa. It is associated with growing in Central and Eastern Europe as well as Russia.

Cannabis ruderalis is the third subspecies of cannabis alongside indica and sativa, it is a small, hardy plant that flowers automatically with age and is naturally low in THC.

At a glance: Cannabis ruderalis

Where does Cannabis ruderalis come from?

Ruderalis was first described in 1924 by Russian botanist D.E. Janischewsky while he was studying wild cannabis in the Volga River system and realised he had found a species of cannabis plant.

The first description came from plants growing in southern Siberia, but they also grow wild in Russia, Central, and Eastern Europe.

Botanists still debate how to classify cannabis ruderalis. When it was first described in 1924, it was treated as a separate species, but modern genetic studies group them under one species, Cannabis sativa, with ruderalis being a subspecies of it.

It is native to harsh climates where growing seasons are short and plants cannot rely on autumn’s light cues to finish reproducing before the first frost.

The name ruderalis explains the plant's habitat. 'Ruderal' comes from the Latin word Rudus, meaning rubble. A ruderal species of plant is the first to colonise disturbed land, much like a weed. In botanical Latin, ruderalis translates to weedy, and wild cannabis ruderalis has grown for centuries as a roadside weed.

Wild ruderalis is small in stature, growing between 30-80cm with a thin main stem and only a few side branches giving it a sparse 'weedy' look, and flowers are small.

Ruderalis is cross-bred with indica and sativa for one main trait: it flowers automatically with age rather than in response to light.

Indica and sativa only flower when the days shorten, so growers need to control their light cycles carefully.

Crossing them with ruderalis produces autoflowering hybrids that keep the cannabinoid profile of indica or sativa; they also flower on a fixed timetable, are quicker to grow, and hardier, which makes them easier to cultivate.

The resulting hybrids are larger, bushier, and have more dense flower buds.

Ruderalis vs indica vs sativa

The cannabis ruderalis plant is one of three common subspecies of cannabis plants alongside indica and sativa.

Sativa plants grow taller, between 2-4 metres, with narrow leaves and have a long flowering period; they’re more associated with uplifting effects.

Indica plants are short, between 1-2 metres, and bushier with wide leaves and have a shorter flowering period and are associated with sedating effects.

For a full breakdown on how cannabis types differ, see our guide to indica vs sativa.

Why ruderalis flowers automatically

Unlike other cannabis plants ruderalis is ‘day-neutral’ which means day length and light doesn’t control when it flowers.

Indica and sativa plants flower by measuring day length, a process called photoperiodism. Most cannabis plants stay in their leafy green growing stage until autumn and begin to flower when the days shorten.

Ruderalis moves into flowering once it hits a certain age, usually three to four weeks after germination and can flower even under continuous light.

This trait is an adaptation to the short growing seasons, researchers believe autoflowering came from high-latitude cannabis populations. The same paper identified the genes behind this trait. The main one is Autoflower1 which is a recessive gene and the plant needs a copy from each parent to flower automatically. 

A second gene, Autoflower2, has also been found and suggests autoflowering developed more than once in cannabis.

Ruderalis cannabinoid profile and effects

Ruderalis is naturally very low in THC, the compound in cannabis that causes intoxication; wild plants tend to have proportionally more CBD cannabinoids than THC, but levels are still low.

Ruderalis is not often used as medical cannabis as a standalone strain.

Pure ruderalis does not produce a meaningful high because of its low THC content, which is why it is rarely grown for medical cannabis or illegal, recreational use.

Instead, breeders may cross it with indica or sativa to develop hybrids that are easier to grow while keeping the cannabinoid levels of sativa or indica.

Ruderalis and medical cannabis in the UK

Ruderalis autoflowering subspecies are not commonly used for growing medical cannabis in the UK because they don’t suit the way licensed producers work.

Licensed producers usually grow medical cannabis from clones, which are cuttings taken from a single mother plant; this makes them genetically identical, so every batch has the same cannabinoid profile.

Autoflowers can be cloned, but cuttings keep the age of the parent plant. That means they start flowering straight away while they are still small, and it produces very little.

Autoflowering subspecies like ruderalis are grown from seed, and why they’re poorly suited to producers who rely on clones.

Frequently asked questions on ruderalis

Does ruderalis make you high? 

Ruderalis naturally has low THC levels, the cannabinoid that causes the 'euphoric' sensation; it won't produce a 'high' on its own.

Is ruderalis high in CBD?

Wild ruderalis contains proportionally more CBD than THC but levels vary between plants and data on it is limited.

Is ruderalis an autoflower?

Yes, ruderalis is naturally autoflowering, meaning it starts to flower with age rather than when days shorten.

Do all autoflowers have ruderalis genetics?

Most commercial autoflowering strains can trace their traits back to ruderalis. But genetic research suggests autoflowering developed more than once in cannabis.

Can you smoke ruderalis?

Possessing cannabis without a prescription, including ruderalis is illegal, in the UK and prescription medication should be vaporised, smoking cannabis is always illegal.

What is the difference between ruderalis, indica and sativa?

Ruderalis is small, flowers with age, and has low THC content. Indica is short and bushy, while sativa is tall and narrow; both flower with light and are higher in THC content.

Is cannabis ruderalis legal in the UK? 

Like all cannabis, ruderalis is a Class B drug under the Misuse of Drugs Act 1971. Growing without a Home Office license is illegal and a prescription only covers the product you’ve been prescribed.

To find out if you are eligible, try our free medical cannabis eligibility checker, it takes less than 30 seconds to fill in.

Our medical cannabis glossary can also help you learn more about terms you may associate with medical cannabis. 

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