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autoflowering cannabis seeds explained

Autoflowering Cannabis FAQ: 7 Must-Know Facts

Autoflowering cannabis varieties have been steadily gaining in popularity over the last five years or so, as improved breeding techniques have created new and better strains. Now, it is possible to grow abundant, high-potency harvests in as little as nine or ten weeks, from germination to harvest.

Autoflowering seeds are a relatively new innovation in the world of cannabis cultivation. Descended from Cannabis ruderalis genetics native to Russia and Central Asia, autoflowering plants do not rely on changes in light cycle to commence flowering; instead, they rely on a different set of triggers, and flower according to age and size.

1. What is Cannabis ruderalis?

Cannabis ruderalis is a putative third species (or subspecies) of cannabis, and is found in northerly latitudes of the northern hemisphere, particularly in Russia. C. ruderalis is notable for its small stature, low cannabinoid levels, hardiness and cold-resistance — and of course, the tendency to flower regardless of light cycles once a certain age and size has been achieved.

Some botanists classify it as a species in its own right, others that it is a subspecies of Cannabis Indica or Cannabis Sativa. In 2003, chemotaxic and genetic analysis of cannabinoid variation in 157 varieties of cannabis indicated that C. sativa and C. indica were two separate species, and that C. ruderalis is a subspecies of C. sativa. However, even this is disputed. In 2005, new analysis revealed that C. ruderalis may indeed be a species in its own right, and a ‘sister’ species to C. indica and C. sativa.

Due to the extreme climate and short growing season of C. ruderalis’ natural habitat, it has evolved to grow, flower and seed in a short period of time, and does not wait until the light levels drop at the end of summer to begin flowering. At this time frosts will already have begun to set in and temperatures will become unfavourable. Instead, once the plant has produced four or five branches and reached a height of around 50cm, it will begin to flower.

Qualities of the C. ruderalis include:

  • Short vegetative periods and short flowering periods
  • Not dependent on light/day cycles to begin flowering
  • Is hardy and resistant to frost and cold climates
  • Always found at 50°N of the equator or even higher latitudes.

2. What are commercial autos and super-autos?

Over the last decade or two, breeders have experimented with crossing C. ruderalis genetics with desirable, high-cannabinoid strains to produce commercially-useful autoflowering hybrids. It is possible that certain other autoflowering landraces may also have played a part in developing the first “autos”, such as a plant known as the “Mexican Rudy”. As the name suggests, this was a ruderalis-type plant found in Mexico. It was used to produce LowRyder, one of the first commercial autoflowering strains on the market.

The first wave of commercial autos, including LowRyder, were typically very small in stature (usually reaching a maximum of 40cm in height), low in cannabinoid content, and somewhat lacking in flavour and potency.

However, successive generations of crosses and backcrosses have led to the development of a range of higher-potency strains that are generally known as super-autos. Super-autos are also typically much taller and bushier than standard autos and their ruderalis ancestor, and may reach 90-100cm in height.

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3. Autoflowering plants do not need darkness

As autoflowering plants are not dependent on changes in the light cycle to commence flowering, they can successfully be grown using a lighting cycle of anything from 16/8 to 24/0. Many growers cultivate their autos under a 24/0 regime; however, some growers believe that anything over 18/6 is overkill and that electricity costs can be reduced with no reduction in final yield.

There is also the possibility that certain hormonal and metabolic processes do occur in darkness, and that allowing your plants to have a “rest” at night-time leads to overall increased health and vigour. However, this is purely anecdotal and there is no empirical evidence to back this up, at least in the case of autoflowering cannabis.

4. Autos can be grown outdoors year-round

If you are lucky enough to live in a mild to warm climate suitable for outdoor growing, the possibilities for growing autoflowering strains are endless. Taking as little as 8-10 weeks from seed to harvest, it is possible to achieve five harvests or more per year if conditions are favourable year-round.

Plus, autoflowers are so hardy that they will grow well as long as conditions remain above freezing. Autos are generally frost-resistant, but permanently-frozen conditions are too much for even the hardiest plant to tolerate.

However, it is important to remember that autos are not fully stabilised in every case (buying seeds only from reputable outlets reduces the risk here) and may take considerably longer than stated. Despite this, even the autos that take the longest to grow outdoors (18 weeks from seed to harvest seems to be the upper limit) are still favourable compared to photoperiod-dependent plants in terms of total grow time.

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5. Can you clone autoflowering plants?

This difficulty in cloning autos has led to the general belief that autoflowering cannabis cannot be cloned, as cuttings taken from a mother plant are forced to follow her “genetic timeline” and flower according to age at the same time that she begins to flower. This logic dictates that the cuttings will not reach a useful size, and yield will be negligible.

However, there are some growers that believe otherwise, and who have successfully managed to clone their autos and allow them to continue to grow in vegetative mode, until they are almost as large as their mother. Once they reach their maximum size, they begin to flower.

The key requirement if attempting to clone autoflowering plants is to take cuttings from the lower branches only. These lower branches seem to be more hormonally stable than newer growth at the top of the plant. The main terminal stem, known as the apical meristem, is the first part of the plant to receive the signal that it is time to flower, and this information takes time to permeate downwards and signal the lower branches to flower.

Thus, there is a brief window of time between the first appearance of sexual characteristics (assuming that regular, non-feminized auto seeds are used) and the permeation of flowering hormones throughout the tissues of the plant. This window may be just a few hours, and it is therefore crucial to watch your plants for pre-flowers and take cuttings as soon as they appear.

Once cuttings are taken, they should be kept under low-intensity light in moist conditions until they have rooted. Once rooted, they will undergo vegetative growth until they have reached approximately 80% of the mother’s size, and will produce comparable final harvests.

6. When do autoflowers flower?

For most plants, including regular cannabis strains, there is a gene that controls photoperiod dependency and response. Obviously, in autoflowering plants, this gene is lacking, meaning the plant does not flower as a response to changes in the circadian rhythm.

Scientists still don’t know exactly which gene is responsible for flowering with autoflowering varieties. However, we do know that in this case, flowering is triggered by age rather than changes in light. Most autoflowers will begin to flower between 6 and 8 weeks after planting.

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7. How long do autoflowers take from seed to harvest?

Given the fact that autoflowering varieties are generally still a new initiative in the world of cannabis genetics, the time between seed and harvest can vary greatly. In general, a good autoflowering variety should be ready to harvest within 10 weeks of planting. With that being said, this is not always the case.

Autoflowering plants have been reported to take up to 18 weeks between seed and harvest. This might be due to instability in the genetics or perhaps an unreliable seed purchased from an unreliable retailer.


70 thoughts on “Autoflowering Cannabis FAQ: 7 Must-Know Facts”

1. Which one of ruderalis tissues has more beneficial components for Business goals؟
2. What is the harvest per hectare?

I’m afraid I am unable to answer this question as it’s outside of our area of expertise. Sometimes our other readers will be able to offer their opinions though. Sorry I can’t help you further, and I hope you continue to enjoy the blog.

With best wishes,

In a Dunum, you can fit about 2000 plants assuming the seeds are regular seeds. However, when you go to an actual outdoor field, you’ll see much higher densities, but that is because the farmers rely on a much longer growing season and they remove the male plants to give the females more breathing space.

That being said, you should not expect more than 2 ounces per plant (regular seeds) under such conditions.

Regarding your first question, I cannot answer that. You must ask God.

How you can ask question like that?! Same like what is the harvest per meter square?! Next time use simple logic if you can!!

In the article it says “Thus, there is a brief window of time between the first appearance of sexual characteristics (assuming that regular, non-feminized auto seeds are used) …”
Why would it matter if the seeds are regular or feminized?

If the seeds are feminized, there is no need to watch out for male plants as none should be produced.

With best wishes,

I believe it is because the author was trying to say that males will appear first, followed in a few days by the appearance of female flowers.

Can anyone help. Im doing my first grow and im a bit confused with this. I am in flowering stage atm and wondering do I just carry on giving them 18/6 light schedule until harvest or is it same as photoperiod plants?

No g,u have to shift for 12h period
18/6 for veg
12/12 for flowering

No. Ignore Atumae. Autoflowers will flower regardless of photoperiod. They flower in regards to the age of the plant.

Only issue you might have to worry about is having a bag seed that is a make pollinate your autos, otherwise you should have good results

So if growing is illegal there then why do you sell seeds there? You said you cant ship the US for the exact same reason. BTW marijuana is becoming more and more legal across the USA, so when do you plan to start shipping seeds here? I mean, there are a lot of fake companies out there selling your product anyways, and they ship here.

Growing is legal in the Netherlands under certain conditions: you may only have five plants or less, and they have to be grown outdoors. Some other European countries are also allowing cultivation with permits, or under similar conditions. We have many customers in those countries.

There are also many countries that permit buying, selling, and possession of seeds, but not their cultivation. For those countries, we sell seeds as collectables and souvenirs.

We would love to send seeds to the US, but even though many states are now permitting cannabis growing, it is still illegal under federal law. Additionally, seeds of any kind being sent to the US need to have the correct agricultural certification; this is something we would have to take care of even if our seeds were legal to ship there. (There are many shops here that sell tulip bulbs as souvenirs, and advertise the fact that their bulbs come with the certificate that makes it possible to take them into the US.)

I can’t speak for the companies that claim to sell our seeds and ship them worldwide. Our terms and conditions clearly state that we only sell our seeds on the condition that they are used in accordance with local and international law.

I hope this answers your question, and that you continue to enjoy the blog.

With best wishes,

If I grow Fem AF seeds outside in same garden as standard bag seeds will they be messed up by any of the non-fem standard plants as they grow together ?
I was hoping to get a 10 week harvest from AF while standard plants grow over the summer.

For legal reasons, we can’t answer direct questions about growing in the blog comments, unfortunately. Our readers will often help each other by sharing information and answering questions, though, which we completely encourage! This article about how to identify male plants might also be of interest to you, as bag seed will contain regular seeds which will produce both male and female plants. I hope this helps, good luck with your gardening!

With best wishes,

Can you chemically remove the auto from an autoflower strain? Im having an argument with my tissue culture guy and hes bet me 10k that he can just remove the autoflower aspect of a strain making it a standard photo peroid. I told him that autos are not chemically made like feminized but are autos because of them being breed with a ruderalis with an indica or sativa. If the ruderalis was removed you would be making a new strain or something that is nothing more than the other parent besides the ruderalis. Is my thoughts correct?

To my knowledge, the only way to stop a strain being autoflowering is to breed the autoflowering traits out of it that were bred in from ruderalis in the first place! However, depending on what type of tissue culture we’re talking about, your contact may have another way of doing it. If this is the case, I’d love to know how it would be done. Let us know if he tells you

Autoflowering vs Feminized: What’s Best for a Casual Grower?

Learn all about the difference between autoflowering and feminized genetics to make an informed choice when shopping for cannabis seeds

When you go to a seed shop, the most conspicuous categories you see there are ‘autoflowering’ and ‘feminized’, so most growers face a difficult choice: autoflowering vs feminized. Let’s look at the advantages and disadvantages of each.

Table of Contents

Autoflowering vs Feminized Seeds

Let’s start with a disclaimer: it’s not really correct to contrapose these two. A seed can be both feminized and autoflowering, or have just one of these characteristics, or neither of them.

‘Feminized’ means that the seeds produce only female plants. ‘Autoflowering’ means that the seeds will automatically start to flower as soon as they are mature enough (let’s say in 2-4 weeks from sprouts).

What are auto feminised seeds then? Well, those that flower automatically + produce flowers that are always female (i.e. buds).

In contrast, the seeds that produce both male and female plants are called ‘regular’, and those that won’t start to flower until you change the light cycle for them are called ‘photoperiod’.

So, seed shops make the bulk of their sales with the following two:

  • feminised auto seeds (mostly referred to as ‘autoflowering’)
  • feminized photoperiod seeds (mostly referred to as ‘feminized’)

And these two are exactly what we are going to compare.

Advantages of ‘Feminized’ Seeds vs Auto Seeds

They Have More THC

When I myself started growing weed many years ago, I was ignoring autoflowering strains completely. At that time, they really weren’t good enough. Over the years, though, the situation has changed.

Today’s autoflowers routinely have around 20% THC. This is an unheard of level for most photoperiod varieties that I used to grow and considered ‘strong’. Still, if a breeder takes some exceptional genetics with say 25-28 percent of THC and makes an autoflowering version out of it, the THC content in the resulting auto flower is always lower. Compare, for example, such a legend as Gorilla Glue with an autoflowering Gorilla.

Autoflowering vs Feminized Yield Per M 2

Autoflowers have a shorter life cycle, so it’s only logical that they produce less buds in the same growspace. Again, some autos can be significantly more productive than some photoperiod strains, but, within the same genetic line, the auto version always yields less grams per m 2 than the photoperiod one.

The Difference in Yields Per Plant Can be Colossal

Photoperiod strains can be vegged for as long as it suits your needs. This allows you to grow your plants into real giants. It’s hardly practical indoors, but outdoors you can harvest as much as several pounds of dry bud from every ‘tree’. Growing fewer but bigger plants is also convenient when there are legal limits as to the number of plants you are allowed to grow.

They Leave More Room for Rookie Mistakes

Novice growers tend to make mistakes from day 1, so they run into trouble long before the flowering stage begins.

With a photoperiod variety, you can simply find a solution to your problem, take necessary measures, and wait till your plant is in good shape again. And only then you change your light schedule to 12/12 to induce flowering.

Autos, on the other hand, don’t wait till you correct your mistakes. Even if they are small and sickly, they are ‘on the clock’ and will start flowering despite their pathetic condition. The result — tiny plants and puny yields.

That being said, I have seen autoflowering strains that are a little more flexible than that. They start flowering when they reach a certain size and have a certain number of true leaves (let’s say 4 developed pairs of true leaves and the 5th one just forming). This can happen after 3 weeks from sprouts (when everything has gone well). Or, if the initial growth was very slow due to bad conditions, they can postpone the flowering till week 4 or even 5. Not all autos behave this way, but some do.

They Let You Take Clones and Keep Mothers

If you like a particular feminised plant and want to keep it for future use, simply take a clone, root it and keep it under 18 hours of light a day indefinitely. This plant will never flower, but will keep growing new leaves and side shoots which you can use for cuttings.

Theoretically, you can take clones from autoflowers, too, but you can’t stop them from flowering, no matter how many light hours you give them. So the only way to propagate your favorite autoflowering genetics is to force the plant to self-pollinate and produce seeds.

You Can Re-Veg Them

To reveg means to revert your plant back to growth after harvest.

A harvested plant is hardly more than a stump with a branch or two and some leaves. But you can turn this pathetic remnant into a full-fledged plant. It can then give you a second harvest or be turned into a mother plant and a constant source of clones.

Obviously, autos can’t be revegged.

They Let You Save on Electricity During the Flowering Stage

Feminized plants spend their 8-10+ weeks of flowering under a 12/12 regime, meaning you burn electricity for only 12 hours a day. The saving can be especially significant if your electrical company offers night rates. For autoflowers, the standard light/dark cycle is at least 18/6 (more hours, more money).

Advantages of Autoflowering vs Feminized Seeds

You Can Grow Them Outdoors in Practically Any Climate

I happen to live in a region with very harsh weather, so I know this firsthand. I started with feminized photoperiod strains and only chose those that were early finishers and tolerant of cold and even frost. Nevertheless, it was always a lottery. Some of those ‘quick’ feminized seeds didn’t even start to flower before the first snowfall. Others didn’t reach full maturity.

Later, I would grow from clones using genetics that had proven to really finish early, but even they didn’t perform equally well every year. It all depended on the weather in the crucial 3-4 weeks in late September – early October.

After I tried an autoflowering strain for the first time, I’ve never bothered to grow a photoperiod variety outdoors ever again. Except maybe as an experiment. As an auto grower, you have an opportunity to choose the warmest, sunniest 2-3 months of the year to complete the whole cycle—from seed to harvest—and count on your buds becoming fully mature.

You Can Have Two or More Consecutive Harvests Per Season Outdoors

It all depends on your climate. If the growing season (with no frosts) in your region is 150 days long, you can easily have two back-to-back auto grows. It’s sometimes very convenient to have several smaller harvests than one large one per season.

One reason is that trimming is a very time consuming procedure. Also it’s nice to have some fresh buds to smoke in the middle of summer, while you’re waiting for the bulk of the harvest that which be mature in fall.

With Autos, You Don’t Worry About Light Pollution

If you grow photoperiod marijuana outdoors, nights during the flowering stage should be dark. Weed plants don’t mind the moon and stars, but react badly to city lights. Indoors, you must make sure that your grow space is completely sealed off and doesn’t allow light leaks. With auto flowers, you don’t have these issues.

You Can Have Both the Vegging and the Flowering Plants in One Grow Room

For photoperiod feminized varieties, you must dedicate two separate rooms. In one, lights will be on for 18 hours a day (the veg room), in the other — for 12 hours a day (the flowering room). This is something that not every amateur grower can afford. As for autos, you can keep several generations, each at a different stage of maturity, under 18/6.

Autoflowering vs Feminized Size

Autos tend to be much smaller. This is very convenient for tight spaces and micro grows, or if you want your secret garden to be inconspicuous.

Autos Finish Faster

Theoretically, you can find a photoperiod strain that grows very fast in veg and has a very short flowering period. So, by inducing the flowering early, you can make it finish in 10-11 weeks from seeds. But this is what an average auto can do without any hassle, and some are much faster than that. So, if you want to end that T-break of yours a.s.a.p., choose autoflowering cannabis.

Now you have a sort of a checklist that will help you decide if you’ll be better off growing feminized seeds or autoflowering. We’ve also written a separate post comparing feminized seeds vs regular. Be sure to read it, too!