“phenomenon” to another, one has to wonder to what extent these new developments will improve the growth and sustainability of this multidisciplinary enterprise moving forward. For example, the seemingly systematic adoption of cannabidiol (CBD) as a panacea has made for its rather ubiquitous integration into a wide range of household products, from creams and lotions to condiments and beverages.
Unfortunately, this has led to an anxiety-fueled mania that has triggered exponential growth in the cultivation of Group III cannabis (hemp), which ultimately triggered a precipitous decline in hemp commodities pricing, with many farmers and entrepreneurs holding the bag. One could argue that the unregulated surge in hemp cultivation fueled its demise and did not make a resounding, beneficial impact on the cannabis industry for more than a couple of years.
With that in mind, is there something else out there on the cannabis cultivation horizon, beyond the mass production of a single cannabinoid, that can have a lasting and sustainable effect on this burgeoning industry? The answer may come from a humble origin.
Cannabis ruderalis genetics originated from Asia and Europe, where they adapted to extreme environments and relatively short growing seasons. Ruderalis plants are generally short and stocky compared to their indica and sativa counterparts, but they are most famous for producing flower material that is grown independently of photoperiod. As a result of this characteristic, ruderalis-based varietals are often referred to as “auto flowers,” as they uniquely flower in conjunction with producing vegetative mass, appealing to those interested in growing cannabis and exploring different cannabis strains.
Ruderalis genetics are often unfairly characterized by the slang term “ditch weed,” which is a reference to the plant’s robust ability to grow almost anywhere, such as the barren terrain one might find on the side of a railway line, as well as its relatively low phytochemical content. Many associate ruderalis varietals with “fiber-type” hemp, which generally expresses very low levels of primary cannabinoids (THC, CBD, CBC) and little to no terpene content.
Nonetheless, the latest commercially available auto-flowering genetics have made great strides in recent years, both in phytochemical production and in ease of use.
Opportunities with autoflowers
One of the most compelling attributes of auto-flowering varieties is how easy they are to grow. Because of their independence from the traditional photoperiod, auto flowers, or “autos,” can be grown by anyone, from a renowned Master Grower to a keen newbie with little to no experience growing cannabis.
Imagine going into your local grow store and buying auto flower seeds or an auto seedling in a five-gallon pot of premium soil that you can then put on your porch or in a window to enjoy cannabis cultivation on the most accessible level. It’s akin to the “set it and forget it” style of making a delicious pot roast (pun intended!) in your Instant Pot while spending time away from the kitchen.
As the perception of cannabis as a viable medicine is continuing to expand well beyond the initial subculture, auto-flowering varieties could be the gateway for any untrained yet interested party to dabble in personalized cultivation, thus making cannabis strains more approachable for the masses.
Even enthusiasts with a small backyard greenhouse or a single 4-by-4 grow tent can produce dispensary-quality medicine with the correct auto-flowering genetics (Figure 1) because most elite-level auto-flowering varieties express all of the same medicinal benefits and phytochemicals (cannabinoids, terpenes, and flavonoids) as their photoperiod counterparts, with the additional ability to grow and flower pretty much anywhere in the world.
Furthermore, using regular, non-feminized auto seed for food and textile crops is a reproducible process that could create unique economic opportunities for developing nations with very little capital investment or infrastructure required.
Additionally, like any other gene, auto-flowering analogs of specific photoperiod strains can be produced through selective breeding cycles. The ability to breed auto-flowering characteristics into different cannabinoid types and strains of cannabis has allowed the industry to enjoy a much more robust repertoire of options compared to the undesirable ruderalis genetics that occupied grow rooms as little as five years ago.
Another positive characteristic of auto-flowering varieties is the relative speed of their growth cycles. Autoflowers quickly outpace their photo-dependent counterparts after germination, reaching adulthood after around two to three weeks versus four to six. From there, autos begin their reproductive stage immediately, producing the first pistils that multiply into buds.
But the vegetative growth doesn’t stop at this point. Autoflowers continue to show how specialized they are in producing plant material quickly as they grow in stature rapidly through the first month or more of flowering (Figure 2). After that, outward growth stops, and the plant focuses on producing terpenes and cannabinoids. Usually, cauliflower varieties take 12 to 14 weeks from germination to reach their height of ripeness.
Today’s skilled breeders have created genetics that produce better-quality flowers in an amazing eight to ten weeks from germination. In contrast, common, photo-dependent cultivars need an additional four to six weeks of long-day vegetative growth before their eight to ten weeks of flowering time to achieve the same production.
Challenges with Autoflower Seeds
Autoflowering genetics have been characterized as generally having poor taste and aroma profiles; in many cases, people say the plants have smell characteristics of fresh-cut grass and hay. Historically speaking, the phytochemical profiles of many autos have been relatively devoid of terpenes and flavonoids. Breeders have been moving forward with these original ruderalis types, dramatically improving their flavor and aroma by mixing them with market-proven cannabis strains and selecting the auto flower traits.
Additionally, there is very little time during an autoflower growth cycle to address critical issues in growing cannabis. If you are not developing commercially, airy buds and smaller-than-average yield are no big deal. However, bud structure, yield, and phytochemical content can be make-or-break issues for a farm operating on thin margins.
Understanding how to optimize growing conditions and feeding regimens is critical for the scale production of these genetic types. As we drift further away from the ruderalis tendency and only identify the auto flower trait, we see fewer and fewer of these issues. But we must feed these plants for dense flowers, having a readily available source of organic nutrients available in the soil for uptake.
The central selling point of an autoflower is its ability to flower under myriad lighting cycles. However, this is also a downfall of this type. If you identify a winning phenotype, taking a clone that can be perpetuated for selfing is impossible.
Even under a 24-hour-a-day lighting cycle, it will continue to flower. Through filial breeding, you can work varieties into a close representation of uniformity, but this is a daunting task, especially when creating feminized seeds.
Many need to use feminized auto-flowering genetics, as the males can and will drop flowers and pollen very quickly after germination. One missed male will pollinate and seed your entire crop. Furthermore, to get an auto to reverse, you must start your chosen reversal method very quickly, leaving very little time to observe each plant’s genetic expression.
To select your donor further into the flower, it is imperative to start multiple plants for a reversal. This takes time, daily observation, and a bit of luck. Ideally, you will find a pair, one male and one female, nearly identical to each other, from which to create your first filial generation. You can further work that line using the aforementioned strategies until you reach uniformity.
Most home growers are okay with different auto-flowering genetics. Still, at a legal market level, the crop batches must be uniform for accurate tests and a consistent product. This is commonly achieved with clones from a mother that are 100% the same.
The inability to clone auto-flowering genetics makes this nearly impossible. Therefore, all auto-flowering genetics must be grown from seed.
Even with a years-long lockdown and a uniform breeding regimen for these genetics, there is always a chance for a genetic mutation in a seed that can be expressed in many ways. It could be as benign as a differing terpene expression or as detrimental as a hermaphrodite that pollinates and dramatically drops the value of your crop.
Key takeaways
When done correctly, one can create an auto-flowering plant that is uniform, consistent, and able to produce multiple crops per year in outdoor or greenhouse settings with very little additional work and no need for supplemental lighting. It is also excellent for locations on the globe with more or less than 12 out-of-12-hour lighting cycles during which typical plants flower before the vegetative cycle can complete or during which there are highly variable lighting conditions.
Autos are plants that, at the base level, are extremely simple and fun for a home gardener or hobby grower. However, strict steps and robust knowledge are crucial to use them at a commercial level. Growing cannabis, especially auto flower seeds and various cannabis strains, requires attention to detail.
It is essential as a commercial grower not to buy auto-flowering genetics from random markets because of the likely massive heterogeneity in flowering times, aroma, flavor, plant morphology, and analytical testing results. However, with all of that being said, it’s time to celebrate auto-flowering genetics and the opportunities that they present for more folks to explore cannabis and hemp cultivation.
Top 10 Autoflowering Genetics
List of commercially-available autoflowering cultivars. Compiled by Diane Young.
| Cultivar | Genetic Profile | Description | Commercial and/or Reference Source |
| Lemon Blueberry Haze | 75% Sativa25% Indica+Ruderalis | Quick finisher with a sativa kick. 24% THC hybrid leaning sativa-dominant. Excellent plant for indoor, greenhouse, or outdoor. No extra training needed. Mold and pest resistant. Energy, motivation, and relaxed muscles are all hallmarks of this genetic. Flower ready 7-9 weeks from germination. Blueberry x Lemon Haze. | Dynamic Research and Development |
| Blue Sherbet Skunktail | 50% Indica50% Sativa+Ruderalis | Complex cross of Blue Sherbet crossed into a Skunk line. 25% THC hybrid. Developed for a small footprint grow. Will grow in a multitude of conditions and grow styles. Candy, OG funk, and strong “melting rubber” flavor profile. A great genetic for pain management, relaxation, and appetite. A quick finisher at 7-9 weeks from germination. Blue Sherbert Skunktail BX2. | Dynamic Research and Development |
| Gorilla Cookies | 55% Indica45% Sativa+Ruderalis | This is a massive producer of golf-ball-size buds that need support. Grows indoors and out, beginner-friendly. Resilient to cold, molds, and mildew. Flowers in 30-40 days. Creative, euphoric, happy high. | 2fast4buds.comherbiesheadshop.com |
| Strawberry Banana | 70% Indica30% Sativa+Ruderalis | Up to 27% THC! It produces an uplifting, creative, euphoric, well-balanced effect. The heavy, massive yield needs to be staked. Extremely sweet and fruity, like a taste of summer. Popular with everyone. Strong euphoria eases aches and stress. | 2fast4buds.comherbiesheadshop.com |
| OG Kush | Indica-dominant+Ruderalis | From a classic strain, Indica-dominant with up to 24% THC. A West Coast fave. Grow outdoors or in. Citrusy-fuel aroma and flavor with a potent punch. Simultaneous mind/body effect with a creative mental energy boost, leaving you happy and relaxed. | allbud.comcannaconnection.com |
| Northern Lights | Indica+Ruderalis | A couch-locker of almost pure Indica for a relaxed, happy, sleepy evening. Old-school aroma and a fruity taste. Aids insomnia, stress, and appetite loss. A short, bushy, resilient, easy grower. | 2fast4buds.comherbiesheadshop.com |
| Purple Lemonade | 70% Indica30% Sativa+Ruderalis | Up to 27% THC. The ideal sweet tooth smoke — uplifting, giggly, socializing treat. Complete body relaxation in the daytime and evening kickback time. Tastes like it smells, of berry with a little lime kick. Easy to grow in or outdoors. | 2fast4buds.comherbiesheadshop.com |
| Lamb’s Breath | Sativa-dominant+Ruderalis | 19-23% THC, with huge, sticky buds in 8-9 weeks. Full body and cerebral high. Skunky, cheesy, pungent smell and taste, with sweet, creamy smoke. | allbud.comherbiesheadship.com |
| Granddaddy Purple | 100% Indica+Ruderalis | High THC! Hashy, skunky taste with a touch of spice. Small, ideal for growing indoors, beginner-friendly. Doesn’t hit you hard after a first big toke. | allbud.comleafly.com |
| Bruce Banner | 60% Sativa40% Indica+Ruderalis | Named for the Hulk’s alter-ego, Bruce Banner is delicate and aromatic, but the 27% THC makes it a bonafide “one hit wonder.” Extremely resistant to pests and mildew. It will put you on the couch, so take it easy with the Bruce. | allbud.comleafly.com |
| Extreme Impact | 90% Indica10% Sativa+Ruderalis | Creative with clarity, it’s a lemon-lime slammer. Grows indoors and out. Unique with a citrusy deep hash flavor and dense smoke. Delay toke-time if there’s still something you need to do. | herbiesheadship.comleafly.com |
| Forbidden Runtz | Indica-dominant | A cross between the classic Runtz and Forbidden ZKittlez. Delicious sweet berry flavor with a touch of pine and diesel. It makes it difficult to think of anything serious. Helps with depression, migraines, stress, anxiety, and other head maladies. Can be body tingling and even a bit arousing! | allbud.comleafly.com |
Zacariah L. Hildenbrand, Ph.D. is the principal founder of Inform Environmental, partner of Medusa Analytical and is a research professor at the University of Texas at El Paso, where his work focuses on educating the general public about the scientific merits of cannabis, as well as developing new innovations with cannabis-based therapies.
Adam Jacques hails from Eugene, Oregon, where he is the lead geneticist at ZED Therapeutics. He is also a technical advisor for Curtis Mathes Lighting. He holds a spot on the Editorial Review Board for Cannabis Science and Technology Magazine. Please send correspondence to adam@zedtherapeutics.com.