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Cannabis cultivation has evolved greatly in recent decades, offering marijuana growers more options than ever. Traditionally, marijuana growers often germinated seeds from low-quality, heavily seeded buds and grown outdoors.

If the grower lived in a suitable climate, they may have harvested buds before fall, but this was challenging with the long flowering periods of imported sativa strains fro countries like Mexico, Colombia, and Thailand.

Advances in cannabis growing equipment and genetics revolutionized American cannabis cultivation. Significant developments included the development of autoflowering and feminized seeds-as well as seeds that are both autoflowering and feminized.

The creation of new strains combining genetics from various countries was once a distant dream. Early cannabis breeders only developed a limited handful of strains, like Haze and Blueberry. The idea that hundreds of interesting strains would be legally accessible to growers was unimaginable in those days.

What Are Autoflowering Cannabis Strains?

The term “autoflowering” in cannabis refers to strains that do not rely on photoperiod to flower. Normal cannabis seeds, as well as feminized seeds, use photoperiod to trigger the flowing stage of growth that produces delta-9 tetrahydrocannabinol (THC)-rich flowers.

Autoflowering cannabis strains are dramatically different than traditional photoperiod plants. While normal and feminized seeds require a change in photoperiod that reduces the light from 18 hours of light and 6 hours of darkness to an even 12 hours of light to 12 hours of darkness to simulate seasonal change, autoflowering strains will develop flowers regardless of whether or not light cycles are artificially manipulated.

Autoflowering strains mature faster, producing harvestable flower in a matter of two months or less, trimming weeks off the time most cultivators typically harvest flower grown from normal seed or clones.

Although light cycles can be manipulated with autoflowering strains, the plants are genetically programmed to produce flowers according to their biological clocks, regardless of photoperiod.

Creating Autoflowering Strains

The creation and development of autoflowering cannabis strains require Cannabis ruderalis, a cannabis species with which many cannabis enthusiasts are unfamiliar.

Cannabis strains are typically lumped into three categories: sativa, indica, and hybrid.

These classifications depend on whether a strain is Cannabis sativa, Cannabis indica, or a hybrid created by crossing these two well-known species. Cannabis ruderalis, on the other hand, was largely ignored for its commercial potential for many years because of its low THC content.

Its countries of origin are also quite different, with C. ruderalis being indigenous to Central and Eastern Europe and Russia, which can have inhospitable climates compared to those of indica and sativa strains.

However, it’s this harsher climate that also gives C. ruderalis its unique and commercially viable differences.

The long warm summer days and harshly cold winter nights of its regions caused C. ruderalis to reproduce automatically in order to survive. If forced to wait until shorter days arrive and photoperiod changes, these plants could easily perish during their first frigid evening when temperatures plummet to unacceptable levels for the plants to thrive until they can produce viable seeds.

As obsessed and ingenious people, cannabis growers and breeders realized that the autoflowering difference between C. ruderalis and the other two species provided opportunities to create a new category of cannabis: autoflowering strains.

One of their main obstacles was the low THC levels of ruderalis strains. Cannabis consumers—including growers—strive to boost their THC levels, and ruderalis does little to increase THC content.

Clearly, there was work to be done to produce both autoflowering and potent strains. Selective breeding and diligence eventually paid off, and potent autoflowering strains were the eventual result—although potency is usually somewhat lower than regular strains.

From there, the creating feminized autoflowering strains was an easily attainable goal. Regular and feminized seeds for autoflowering strains are now available to growers everywhere.

The Pros and Cons of Autoflowering Cannabis Strains

While it’s nice to have options, autoflowering strains are more suited to some growers than others. They have little, if any, value for commercial growers, while home growers may find them very desirable.

Cloning is not done with autoflowering strains, and the commercial cannabis industry relies on clones for the consistency of the product. Cannabis flower sold in dispensaries results from cloning, and you can be certain a mother plant exists somewhere.

Because autoflowering strains flower regardless of their photoperiods, mainlining an autoflowering mother plant by keeping her permanently in 18 hours of light per day is impossible. This is a key shortcoming of autoflowering cannabis, but they have their benefits as well.

Let’s examine some of the key differences between autoflowering and regular cannabis plants by considering the pros and cons of autoflowering strains.


Earlier Harvest

Since autoflowering strains begin to flower at a younger age and size than most people choose to put their regular cannabis plants into the flowering cycle, a decent harvest at 10 weeks is possible, trimming off some of the time it takes to enjoy a harvest.

Short and Stocky Plant Structure

The plant structure of autoflowering strains is shorter and bushier than many plants that rely on photoperiod to flower. As a result, staking and training isn’t necessary for autoflowering plants.


Autoflowering strains are smaller than traditional strains, making them a good option for growers who want to grow cannabis discreetly. Due to their small size, they can be grown in smaller spaces and are easier to hide in balconies, closets, or other locations.

There are No Lighting Restrictions

Autoflowering strains don’t rely on photoperiod to flower, so lighting can be extended if the grower wishes to do so. In addition, the plant isn't as affected by lighting pollution. In photoperiod plants, light pollution can cause stunted growth, reduced potency, and reduced yields.

Hardier and More Resilient

Because autoflowering cannabis plants contain ruderalis genetics, they are typically more forgiving of harsh environmental factors. They are known to tolerate colder temperatures better than strains from the tropics.

A Great Choice for Beginners

Every marijuana cultivator had his or her first grow and undoubtedly made some mistakes along the way. Autoflowering strains are more forgiving and don’t rely on an exact photoperiod, which are two reasons why they are a good choice for beginners learning the ropes.

Perfect for Grow Cabinets and Tents

Because they mature quickly and don’t reach tall heights, autoflowering strains often are perfect for grow cabinets, which sometimes receive criticism for their limited growing space. The height of autoflowering strains once they mature and are ready for harvest is almost tailor-made for grow cabinets.

Year-Round Harvesting

Autoflowering strains can be harvested year-round, regardless of the seasons, making them a good option for indoor growers who want to maximize their yield.I

Indoor and Outdoor-Friendly

Autoflowering strains are ideal for indoor growing, as they have a compact growth structure and do not require a strict light schedule. This makes them a good option for growers with limited indoor growing space.

Autoflowering strains are also well-suited for outdoor growing, as they can handle various environmental conditions and do not require as much attention as traditional strains.

Fewer Resources Required

Compared to traditional strains, autoflowering strains save on energy costs when growing indoors due to a shorter flowering time. They also use less water and fewer nutrients, which can save you time and money.


Lower Plant Height and Yield

Regular cannabis plants will grow in their vegetative stage for as long as the grower wishes. If the grower wishes to produce very tall plants with a correspondingly higher yield, that is easy to do by delaying the reduced photoperiod that results in flowering.

Lower Potency

Although autoflowering strains can reach decent potency that can reach levels in the 20s, regular versions of the same strains will produce higher THC levels. The low THC of ruderalis—the genetics from which are found in all autoflowering cannabis—is the reason for this.

Less Control

Regular and feminized seeds allow the cultivator to choose not only the height of the resulting plants, but when they will eventually mature. Autoflowering seeds result in plants that follow their own schedule, regardless of manipulation of the indoor environment in which they grow.

Cloning Is Impossible

Since autoflowering strains flower regardless of photoperiod, maintaining mother plants for these strains is impossible.

Each autoflowering plant was grown from seed, and there is no way to preserve the genetics of a particularly nice phenotype from cuttings, which is a widespread practice with regular seed.

Limited Genetics

Autoflowering strains are often produced by crossing traditional strains with wild cannabis plants, which limits the available genetics. This means that growers may have limited options when it comes to choosing the right strain for their growing conditions.

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Autoflowering cannabis strains can be more expensive than traditional photoperiod strains due to their genetics, but the faster flowering time and ease of cultivation can offset the cost for some growers.

Choosing the Right Autoflowering Cannabis Strain

There are a number of factors to consider when selecting a strain, such as potency, flavor, yield, and growth characteristics. Here are some tips to help you choose the right autoflowering cannabis strain for your grow:

  • Potency: How strong do you want your buds to be? If you are looking for a strong, potent high, choose a strain with high THC levels. However, if you’re looking for a more balanced or THC-free experience, grow high-CBD autoflowering strains.
  • Flavor: If you have a specific flavor preference, choose a strain that is known for its unique flavor profile. Every strain has a different set of terpenes, the essential oils known for the plant’s aroma.
  • Yield: Consider the yield of the strain, as this will determine the amount of buds you will produce. If you are looking for a high yield, choose a strain that is known for producing a large amount of buds.
  • Climate: Do you plan to grow indoors or outdoors? Certain strains may prefer warm and humid climates. Other strains are less resistant to pests, requiring a climate-controlled environment.
  • Growth Characteristics: Autoflowering cannabis strains are generally shorter than traditional photoperiod plants, but there can be a range in height between autoflowering strains. Lighting and pot size can also affect the final height of the plant.

How to Properly Care For and Maintain Autoflowering Cannabis Plants

To properly care for and maintain autoflowering plants during the growing process, follow these guidelines:

  • Provide ample light: Autoflowering strains require a good light source for optimal growth and development. Make sure to provide at least 18 hours of light per day.
  • Maintain optimal temperature and humidity: Keep the grow room temperature between 68-77°F and the humidity level between 20-40%.
  • Water regularly: Autoflowering cannabis strains do not require a lot of water, but it's important to provide the right amount of water. Avoid over-watering, as this can lead to root rot.
  • Fertilize properly: Autoflowering strains have a relatively low nutrient requirement, but it's still important to provide them with a balanced fertilizer to promote healthy growth.
  • Prune and train: Pruning and training can help improve the shape and structure of autoflowering plants, which can increase yield and overall quality.
  • Monitor for pests and diseases: Regularly inspect your plants for any signs of pests or diseases and take action promptly to prevent any damage.

By following these guidelines, you will ensure that your autoflowering plants receive proper care and grow to their full potential.

Final Thoughts on Autoflowering Cannabis Strains

Love them or hate them, autoflowering strains are here to stay. Very few experienced growers don’t have strong opinions about them because while they suit some people's needs, they also have definite drawbacks and limitations.

Recognize the differences in these strains, and buy some autoflowering seed to grow some plants if your circumstances make this type of cannabis plant desirable.

Gavin Kushman. Cannabis strain writer in a cannabis garden
Gavin Kushman

Gavin is a worldly adventurer and cannabis connoisseur, embarking on journeys that take him to the far corners of the globe to explore and document the varied effects, flavors, and histories of both renowned and lesser-known strains. From the misty high-altitude farms of the Hindu Kush highlands to the vibrant cannabis cafes of Amsterdam, Gavin's quest for knowledge spans continents. A recognized authority in the cannabis industry, he frequently lends his expertise to leading publications such as Cannabis Training University, where his captivating blog articles chronicle his unique experiences with different cannabis strains.

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