Cannabis Ruderalis: A Complete Guide

Everyone has heard of indica and sativa, but what is Cannabis ruderalis? Although it’s the least famous of the cannabis plants, Cannabis ruderalis is important to growers—and really to any cannabis fan—for a few reasons:

  • Ruderalis plants are autoflowering, unlike most cannabis plants which are photoperiod, and can be used by breeders to produce other autoflowering species with more THC.
  • Ruderalis plants have a unique growth cycle that tends to be short, around 10 weeks; this is related to the cooler climates where the plant grows naturally.
  • Ruderalis plants are also excellent for breeding high-CBD strains of cannabis.

Debates about indica versus sativa, or whether those are real categories at all, typically dominate discussions of cannabis strains. Most everyday cannabis consumers aren’t aware of the sub-species with many specific characteristics that appeal to growers: cannabis ruderalis.

In this post, we offer a complete guide to Cannabis ruderalis, including its origins, the differences between ruderalis and other types of cannabis, characteristics of ruderalis and how to grow it, pros and cons of ruderalis, and effects.

Cannabis Ruderalis: The Basics


The name Cannabis ruderalis comes from the Latin ruderal or rudera. Ruderal cannabis plants are a wild species more similar to hemp than classic medical marijuana you come across in a dispensary. Ruderalis plants can survive and even thrive in unlikely environments, such as those that have been disturbed by development or natural disasters. The stories you hear about actual “weed-like” marijuana growing beside a highway might just be about Cannabis ruderalis.

Ruderalis is often referred to as either a third species or a subspecies of the cannabis plant. And although most people are familiar with indicas and sativas, at least if they are cannabis enthusiasts, not as many people are conversant on C. ruderalis.

Native to Central Asia, and most of Russia, and Eastern Europe in regions with a lack of sunlight and short days, the most distinct feature of Cannabis ruderalis is its autoflowering trait. In its original habitats, ruderalis developed the ability to flower independently and initiate a bloom after a predetermined period of time. This sets the plant apart from photoperiod cannabis species that rely on a change in the light cycle to bloom—and that would likely find growing in those climates impossible.

Although ruderalis is known for its ability to grow wild, today breeders use its unique traits to create hardy, appealing hybrids.

Size and shape are the main characteristics that distinguish ruderalis from other types of cannabis, at least based on an inspection with the naked eye. Cannabis ruderalis is significantly smaller, on average 1-2.5 feet high, with broad leaves and small buds. (More on its physical characteristics below.)

Most cannabis consumers aren’t shopping for pure ruderalis strains. It is not known for being loaded with terpenes, and it’s also low in THC. Pure ruderalis plants are also small and yield poorly.

Yet, Cannabis ruderalis has revolutionized the way we breed and grow cannabis. By crossing ruderalis strains with photoperiod strains, we can produce higher THC strains that still flower automatically: the next-gen autoflowering cannabis strains on offer now. This lets even inexperienced growers produce high-quality cannabis even without extensive space or equipment, with no sacrifice to flavor or potency.

Origins of Cannabis Ruderalis

In 1924, well-regarded Russian botanist Janischewski was working in southern Siberia near the Volga River when he noticed a new type of cannabis. In agreement with other botanists, Janischewski concluded that, along with Cannabis sativa and Cannabis indica, the plants were members of a third cannabis species. The scientists based their conclusions on the very different appearance and growth cycle of the plants and named it “Cannabis ruderalis.”

Autoflowering Cannabis Ruderalis

Now it’s important to compare autoflowering and photoperiod cannabis plants, and explain why C. ruderalis is so different from indicas and sativas.

Photoperiod Plants

In the plant world, the climate dictates the number of daylight hours and changes in temperature which in turn controls when flowering plants start reproducing or flowering. How much light and what temperatures are right is different from plant to plant, but for cannabis, 12 hours of uninterrupted darkness during a 24 hours period triggers the flowering cycle.

These kinds of plants are photoperiodic. Photoperiodism among plant organisms is a physiological reaction to a change in the length of dark periods or nights. The reaction itself prompts a change from the vegetative phase to the flowering phase.

This idea is how cannabis breeders take action once they predict when their plants will be ready to start flowering. The optimal flowering time in a cannabis plant’s life varies greatly by strain, but it’s simple to accurately induce photoperiod plants to flower by ensuring they encounter precisely 12 hours of uninterrupted darkness in a 24 hour cycle.

Autoflowering Plants

Ruderalis plants are strikingly different based on their ability to start flowering on their own, without regard to time in darkness. This quality is called auto-flowering or autoflowering, and for C. ruderalis plants, it is overall maturity that prompts flowering. In fact, this is probably the most critical characteristic of Cannabis ruderalis in terms of cultivation.

Cannabis ruderalis plants will usually start their reproductive cycle around the 30-day mark. This can range from 5 to 8 weeks with the various auto-flowering hybrids that are themselves the products of pairing with different cannabis species that flower in their own time. Once the flowering phase starts, the cannabis plant continues to produce flowers until it reaches the natural end of its life—unless environmental factors like winter or extreme changes in the climate cause it to expire sooner.

For cannabis growers, the capacity to reproduce or flower based on the age of the plant makes ruderalis specimens great prospects. Why would growers be interested?

By breeding various popular indica and sativa varietals with c. ruderalis strains, they can create hybrid strains with high-CBD levels. These autoflowering hybrids retain the high-THC content and big buds of non-ruderal cannabis strains that everyone wants yet are still easy to raise for beginner growers.

Unique Growth Cycle

Ruderalis has had to endure various climate roadblocks merely to survive its natural habitat. As a result, this low-THC species has made notable adaptations. Major fluctuations in the duration of night and short, cool summer seasons forced a puzzle of adaptation on ruderalis: reproduce before winter’s freezing climate kills you. These conditions helped the ruderalis plant adapt with a unique growth cycle, completing its life cycle quickly, usually within 10 weeks, and certainly within 14.

Furthermore, even with years going by before ruderalis seeds have had the chance to sprout, the plant’s evolutionary history allows the seeds to survive fully capable of producing a healthy plant. Once favorable conditions have returned and the freezing winter months have passed, the seeds will germinate.

Although ruderalis may not be appealing for medicinal or recreational use on its own, breeders use it to create new cannabis strains because of this autoflowering capability. Ruderalis crossed with high-quality cultivars, whether they be indica, sativa, or hybrid, can produce autoflowering strains that still retain cannabinoids and other desirable traits. This allows growers to keep plants under a consistent light schedule of 18–20 hours a day throughout all phases of growth, significantly reducing stress.

Light schedule aside, a faster grow cycle overall is another advantage of autoflowering strains. This allows growers the opportunity to harvest multiple crops per season, per year, and reduces the risk of weather-related crop loss.

Ruderalis vs Indica and Sativa

Before the 1970s, conventional wisdom thought that there were two Cannabis sativa subspecies: C. indica and C. sativa. But Loran Anderson and Richard E. Schultes, two American biologists, argued in the mid-to-late 1970s, that there are actually three cannabis species: C. indica, C. sativa, and C. ruderalis. Compared to the other two subspecies, ruderalis plants are shorter with minimal branching and have small, broad leaves with four to six blades each.

However, around the same time in 1976, Ernest Small and Arthur Cronquist countered that actually there was just C. sativa, the only cannabis species, although human intervention had created two subspecies: C. indica (high-THC cannabis bred and grown for its “high” and other psychoactive effects) and C. sativa (low-THC hemp). There is no real consensus, as many botanists have since argued that indica and sativa subspecies may have occurred before human cultivation. In any event, few people use the term ruderalis today.

Ruderalis vs Hemp

This leads us to the inevitable question: isn’t ruderalis just hemp if it has low THC levels? No, and here’s why.

Cannabis ruderalis has low levels of THC, usually below 3%, but this is still far more than hemp is allowed to have. Ruderalis and hemp often contain similar CBD levels.

Hemp isn’t a distinct cannabis species. Hemp is, in a sense, a legal term that refers to cannabis that is selectively bred to contain minimal THC levels. To qualify as hemp in the United States, cannabis plants must contain less than 0.3% THC. In Europe, depending on the country, the threshold is 0.2–0.3% THC.

Humans have cultivated hemp for millennia, because it is more versatile than ruderalis. Hemp is grown for many different purposes, including making biofuel, fabrics, food, health supplements, and paper. In contrast, cannabis ruderalis is used for one purpose almost exclusively: breeding.

If the root of the question is a legal one, to be classified as hemp, ruderalis would have to have an unusually low THC content—below the legal limit. Otherwise, like any other cannabis plant, ruderalis is only legal where recreational and/or medical cannabis is legal.

What is C. Ruderalis Used For?

There are a few basic uses for Cannabis ruderalis, despite its relatively low THC content and small yields:

Ruderalis species excel at producing CBD and THC in an even 1:1 ratio. For anyone seeking a more medical strain, autoflowering ruderalis hybrids may present an optimal choice.

Compact size, easy to grow. Especially for amateur home growers who don’t have lots of space and want a manageable, smaller plant that’s easy to grow, autoflowering ruderalis hybrids are a great option.

Quick life cycle maximizes grower profits. For industrial growers in particular, ruderalis hybrids can be an excellent tool for boosting profit thanks to better turnaround time and quick life cycle. Hemp producers also benefit from quicker turnover of active crops. And growers control yield more with autoflowering strains than with photoperiod strains.

Fewer light requirements. Precise light deprivation is no longer an issue for outdoors horticulturists thanks to the short stature of ruderalis hybrids, and ruderalis also reduces light energy costs for indoor growers.

Characteristics of Cannabis Ruderalis

Ruderalis actually behaves and looks different as it is grown compared to standard sativa and indica strains. The ruderalis plant will reach a height of just 1 to 2.5 feet for any grower, making it the smallest of all cannabis types. The short, stocky plants have very broad, wide leaves and thick stems. C. ruderalis typically sports fewer branches and an open leaf structure. Generally, compared to other cannabis plants, a ruderalis bud is smaller and more compact, but still chunky and sturdy.

Effects of Cannabis Ruderalis

You typically won’t find pure ruderalis cannabis in your neighborhood dispensary, assuming you have one, so only the home grower gets to experience the effects of ruderalis. But for pure ruderalis, those are actually fairly tame, and certainly more on the medical marijuana end of things.

Cannabis ruderalis naturally contains more non-psychoactive cannabidiol (CBD), and very little psychoactive tetrahydrocannabinol (THC), so it may have medical benefits although it is less likely to produce a euphoric high.

CBD and THC are the most important of the over 100 cannabinoids that occur naturally in cannabis. Cannabinoids interact with the endocannabinoid system (ECS) in the body via its cannabinoid receptors, helping keep the body’s functions in balance by adjusting the release of neurotransmitters in the brain.

Consumers looking to avoid euphoria and psychoactive effects while retaining medical benefits are often interested in Cannabis ruderalis, as are breeders, who can create high-CBD, autoflowering strains using these plants. 

Pros and Cons of C. Ruderalis

The biggest pro of C. ruderalis is that it produces a relaxing, calming, clear-headed experience—and that’s assuming you’re not a grower or breeder. Ruderalis is good cannabis for medicinal purposes due to its high CBD (cannabidiol) content, especially for medical marijuana patients who want to access the benefits of CBD while avoiding the effects of THC. And thanks to its calming benefits, high-CBD cannabis is typically recommended for people with insomnia or anxiety.

Other pros of Cannabis ruderalis:

  • Autoflowering quality
  • Better resistance to disease, pests, and environmental fluctuations
  • Can grow almost anywhere thanks to hardy genetics
  • Short overall life cycle and fast growth
  • Good for beginners
  • Multiple outdoor harvests (year-round and seasonal)
  • Modern autoflowering hybrid strains are flavorful, potent, and higher-yielding

The biggest con of C. ruderalis, at least for most consumers, is that it produces no significant high. Ruderalis doesn’t cause psychotropic effects due to extremely low levels of THC (tetrahydrocannabinol).

Other cons of Cannabis ruderalis:

  • Low THC levels in pure ruderalis means you need to breed with indica or sativa to add potency
  • Smaller yields due to smaller plants
  • High-stress training and transplanting less possible due to short life cycle

Remember, there’s a huge difference between pure ruderalis and modern autoflowers! These modern strains don’t come with the low yields or potency of the pure variety. In fact, as breeders continue to improve modern autoflower strains, the potency and yield differences between ruderalis and photoperiod cannabis are growing smaller.

Growing C. Ruderalis

Autoflowering strains tend to be particularly resilient and hardy because they flower independently of light cycle. They grow more quickly and easily than photoperiod cannabis overall. Still, there is no substitute for good advice when growing autoflowers.

As long as there is no frost, plant autoflowers at any time of the year. However, as plants can take advantage of better soil conditions and sunlight, spring is still the optimal time to start an outdoor grow for superior results.

It is often preferable to grow ruderalis plants indoors in regions with consistent storms, colder year-round temperatures, or both. However, if you’re fortunate enough to grow in a warm region without frost, it’s possible to harvest ruderalis outdoors year round. Growers can even enjoy multiple autoflower harvests in just one growing season since the plants reach maturity in around 70 days.

Outdoors, protect plants well from the elements by erecting support or positioning plants near shelter without obscuring sunlight. Use companion plants indoors or outdoors to improve soil biodiversity and protect your crop. And use a greenhouse, if you have it.

Although some photoperiod plants reach 2 meters or higher under the right conditions, autoflowering plants are much smaller, and need much less in the way of nutrients. If you’re using commercial nutrients for your cannabis ruderalis, start with less than the recommended amounts. In fact, start low and increase nutrients only for signs of underfeeding. On a standard phase-dependent feeding schedule, it is sometimes even possible to feed ruderalis plants flowering nutrients alone.

Among the most important concerns for anyone who wants to grow Cannabis ruderalis is getting high-quality seed. More often than not, bagseed and seeds from unreliable sources are low quality. This means all of the wasted time, money, and energy—not to mention disappointment—of poor growth, poor germination rates, and low yields.

Is Ruderalis Legal?

Just like the more well-known cannabis indica and cannabis sativa, ruderalis is a subspecies of the cannabis plant, meaning that whichever laws already apply to cannabis, also apply to ruderalis. Wherever cannabis is legal, whether for medical or recreational purposes, ruderalis will also be legal. In general, it would be unusual for C. ruderalis to have a federally legal level of THC in it.

Where Can I Find Ruderalis Strains?

It’s not so easy for consumers to just shop for ruderalis strains at their local dispensaries. Growing ruderalis for commercial sale is just not something growers put much time or energy into. But you can definitely find plenty of the fruits of smart breeder ingenuity in the form of auto strains. These combine native ruderalis cannabis strains with high-THC strains with unique terpenes profiles and favorable growing characteristics, both indicas and sativas, to create the hybrids so many of us know and love more easily.

Common Ruderalis Strains

Some examples of auto-flowering strains that also have higher THC levels and low-to-moderate levels of CBD are:

  • Blueberry
  • Bruce Banner
  • Critical Mass
  • Girl Scout Cookies
  • Gorilla Glue
  • Northern Lights
  • White Widow

Final Thoughts on Ruderalis

Ruderalis hybrids with their shorter heights and fast and efficient life cycles are a critical piece of modern cannabis growing operations. We hope this guide to cannabis ruderalis has been helpful, and happy growing (not to mention smoking)!

Frequently Asked Questions: 

Question 1: Can ruderalis get you high?

This is not a straightforward question. Yes, an individual plant with enough THC could, especially if you consumed enough. However, the well-known downside of natural ruderalis is its low THC levels, especially compared to standard sativa and indica plants.

On the other hand, ruderalis is critical to all modern autoflowering hybrids. So anytime you’re smoking a high-end autoflower bud, you’re definitely getting high from ruderalis, at least in some sense.

Question 2: Is ruderalis high in CBD?

Yes, Cannabis ruderalis is higher in cannabidiol (CBD) naturally and produces less tetrahydrocannabinol (THC). This means more of the non-psychoactive, medicinal cannabinoid and less of the psychoactive cannabinoid responsible for the classic euphoric marijuana high. This accounts for its medicinal qualities.

Question 3: Does ruderalis still smell like cannabis?

Yes, but it is far less aromatic. Ruderalis contains fewer cannabinoids and terpenoids than other types of cannabis, so it is less flavorful and pungent.