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What Is Autoflowering?

Many cannabis growers tend to look at online catalogues to find what they are looking for. And they’ll often come across strains that are ‘automatic’, or more specifically, the ‘autoflowering’ variety.

If you have ever wonder what an automatic strain is, then this article is all you need.

What is an Automatic/Autoflowering Strain?

The premise behind autoflowering strains is a very simple one: as time moves forward, they will ‘automatically’ flower, rather than flower according to a fixed or timed light cycle. Put another way, the cannabis plants flower automatically on their own after a fairly short vegetative period – no more than 2 to 4 weeks.

However, this unique process cannot ensue without folding in genetics from the Cannabis ruderalis J plant, which has actually existed for several thousand years. This cannabis subspecies is very well known for its short stature and autoflowering characteristics.

When you cross the autoflowering ruderalis subspecies within a sativa or indica variety, you get a plant that does not need photoperiods to flower. Instead, it grows and flowers on its own. When mixed with either variety, autoflowering cannabis strains have the ability to produce superb vigour and potency.

Automatic cannabis strains are ideal for growers who are short on time, energy and especially space. In fact in this regard, feminised autoflowering strains are an excellent choice.

Traditional Strains vs. Autoflowering Strains

Let’s quickly pick apart some of the key differences between automatic strains and traditional cannabis strains. Autos do not require any kind of special light schedule that signals the plant to start budding, which holds true for photoperiod/traditional strains. In case of the latter, plants require more than 12 hours of darkness each day in order to initiate the flowering process.

When growing traditional strains out in the open, the flowering process naturally starts once the days get shorter. Therefore, outdoor growers need to plant their seeds in the spring season and choose or pick strains that are capable of fully flowering before winter arrives.

On the other hand, when it comes to growing photoperiod strains indoors, the grower can kick start flowering as he/she pleases – that is, by providing the plants longer dark periods. This can easily be accomplished by timing the grow lights to turn on after a set number of hours. So what this means is, 12 hours of uninterrupted darkness is required each day while the plants flower.

With automatic strains, growers can take a sigh of relief because there are no lighting schedules to worry about. Each autoflowering strain will bloom on its own after a few weeks, irrespective of the light schedule it is subjected to. Outdoor growers of autoflowering strains do not need to match up the strain with their local time zone. Neither are they required to plant it at the perfect time. All they have to do is plant the automatic strain during 2-3 months of consistently warm and sunny weather.

So in essence, there are actually multiple advantages to be had when growing autoflowering strains; the most notable one being that there are no lights schedules required. You only need to ensure that you have three months of warm and sunny weather that’s above 15.5°C – climactic conditions that are ideal for growing autoflowering strains.

So if you’re a grower who needs to harvest quickly before summer is even over, an autoflowering cannabis strain is your best bet.

Harvest Time

Autoflowering strains will only make vegetative growth for the first few weeks, that is, stems and leaves only. Once this short vegetative stage comes to an end, the plant will start producing buds and grow taller, even as the buds continue to form.

Typically, autoflowering plants will stop growing in an “up and out” pattern a few weeks prior to harvest. When this happens, the autoflowering plant tends to divert all its energy toward fattening up the buds.  So don’t be surprised if the buds gain a reasonable amount of weight during the last couple of weeks.

When you purchase autoflowering seeds from a good and reputable breeder, they’ll let you know how long the strain requires to “autoflower”. However, you might have higher potency and produce better yields by leaving your autos a week or two longer than the recommended autoflowering period.

Photoperiod or traditional cannabis strains take a lot longer to harvest. Usually they are ready to harvest within 3 to 4 months after they have sprouted from the seed. However, the actual duration hinges quite heavily on your specific grow style and the strain you choose. In addition to the longer harvest time, the yields are also typically much lower.

Photoperiod plants perform at their level best when they are given a reasonable amount of time in the vegetative state before they can start flowering. They are also not well suited to quick harvests.


Autoflowering seeds typically yield up to 4 ounces of bud for each plant, although the amount of bud that’s produced is also dependent on the grow setup.

It’s not unusual for growers to yield only 1 to 2 ounces per autoflowering plant or even less – particularly in situations where they start off with poor genetics or rely on a mediocre lighting setup. It’s important to remember that just like any cannabis plant, autoflowering strains also need a fair amount of light to produce the best yields.

Unsurprisingly, growers who start off with great genetics, ideal conditions, and also have a fair amount of experience can easily yield as much as 6 ounces or more for every autoflowering seed.

On the subject of yields, it’s good to remember that a key advantage of growing automatic strains is that you can produce multiple harvests every year – given the short lifespan of every auto plant.

Photoperiod or a regular strains, on the other hand, vary a lot in terms of yields. This is mainly due to the fact that growers can exercise a lot more control over plant attributes like shape and size. This in turn, affects yields in a major way.

When growing all outdoors, yields will depend a lot on the climate. For instance, warm and sunny climate with several hours of light each day will produce bigger yields.

When going indoors, your growing setup is the single most important factor that determines yields.

Pros and Cons of Autoflowering Cannabis Strains 

Just to quickly touch again on some of the previous points, there are many reasons that you might want to consider the autoflowering variety for both indoor and outdoor growing:


When grown outdoors, these strains will start to produce a lot of buds irrespective of how much sunlight they receive each day. This means you never have to worry about having a timed lighting setup, particularly if your aim is to have multiple harvests per season.

When you grow them indoors, auto seeds let you rapidly grow plants from start to finish, because they have the ability to complete maturation after just three months.

Autoflowering strains are capable of easily withstanding over 12 hours of sunlight per day and still yield bigger buds in significantly less time as opposed to regular strains.

Auto strains are small and stealthy which means they are ideal for growing outdoors or ‘closet grows’, because not every grower wants their neighbours or bystanders to see what’s going on – and that’s completely okay!


However there are a few reasons so as to why autoflowering strains may not be the best choice, compared to regular sativa and indica plants.

Autoflowering strains are generally small stature-wise and are not capable of producing large yields.

Autoflowers require more electricity if grown indoors.

As a grower you don’t really have the ability to train your plants a certain way in order to capitalise on your grow space.

With this out of the way, we would still say that the Pros far outweigh the cons.  Autoflowers have indeed come a long way and there have been major genetic improvements since. First of all, potency in autoflowering strains has dramatically increased since they were first introduced.

Second, there are now several hundred varieties to choose from. Because of these improvements alone, automatic seeds are a good choice for any curious grower who wants to try something new and non-traditional.

Medical Cannabis: Autoflowering Strains May be Better

Autoflowering strains may provide a lot of benefits for medical marijuana users because they tend to have higher CBD levels than photoperiod strains.

CBD is the main cannabinoid found in marijuana that offers medicinal benefits including anti-anxiety and anti-inflammatory properties. In contrast, majority of photoperiod strains available nowadays are very high in THC and low in the health promoting CBD.

This makes autoflowering seeds a very attractive choice indeed for medical marijuana users. In fact, there are specific autoflowering strains that are purely bred to have a high CBD content.

Closing Thoughts

If you’re a new grower then you should definitely try out autoflowering strains. More importantly, if you consume cannabis purely for medical reasons, autoflowering strains are the way to go.


Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.


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