Auto flowering, will someone please advise me here and tnx

can someone give me a basic course, not up on them yet…

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@Majiktoker @pigSquishy and @rjw71 have helped me a lot. From what I understand, learning I had been given one as a seed, things are sped up quite a bit.

I do know you don’t have to reduce light time for them. I don’t know how your grow is being done, mine is outside in a container. I fed her once with a super bloom fertilizer about two weeks into flowering. Potted with M G not knowing she was an auto.

I just cut her Saturday night, so I can’t really tell you what that soil with that feeding did for her quality yet, but she was pretty. Small, but pretty.

Speaking of small, do not top or super crop her. I started topping before I realized she was an auto. Did a little low stress training and she was only about 12" from the soil to the top. 4nice main colas with one other small one. The rest of the little buds will end up being turned into keif.

My other auto, same scenario as above from seed, I never topped. I DID cut some bottom branches for cloning before discovering she also was an auto.

I believe had I not cut those bottom branches, I would now have a 2’ cola standing outside perfuming my yard. Not to mention, the clones are not doing well IMO.

There are plenty of people here with plenty of knowledge and experience that are willing to help. I would also suggest downloading the grow guide from ILGM, read the whole thing and listen to advice here.

Good luck with it. I see how fun an auto can be, just wish I had known what I had when I planted her. ILGM can help with that too :wink:.


As we all know, cannabis is a photo-period plant: ie it’s flowering hormones are triggered by changes in the light/dark cycle. Thus you can stimulate a 2 week old cutting to begin flowering by giving it 12 hours of darkness, yet a 4 month old plant grown outside will remain in vegetative growth until mid-summer has passed.

Autoflowers are a different breed altogether (quite literally!) and will flower according to the age of the plant rather than the light/dark cycle. This development has been obtained by crossing a ruderelis strain with a standard photo period plant. Unfortunately ruderelis is fairly weak in the desired thc levels so the first autoflower strain developers had to stabilise two dominant traits: the high thc level provided by the photo-period parent and the all important auto gene from the ruderelis strain. As you can expect, early attempts were generally disappointing, and as little as four years ago autos were viewed as unreliable with poor yields and low thc levels. Most sensible growers put them down as gimmicks for newbies.

Today if you see an autoflower seed for sale you can be (reasonably) assured that its THC content will be as advertised, and its auto gene stabilised.

Now this is the big question. Most breeders claim 7-9 weeks, with some even boasting seed to harvest in less. It would be fantastic if one could get 50g per plant after just 39 days, but lets face it, its totally unrealistic. A plant doesn’t grow any faster for having an auto gene, and the dwarf autos that will harvest in ultra quick times are just that: dwarfs and thus yield is limited by size.

Of the 15 or so different commercial strains I have tried, not one of any consequence finished in less than eleven weeks – and the best ones can take anything between 3 and 5 months. If you think about it, this is not surprising: most standard autos start showing their sex at around 21 -28 days (super autos not included) – if you add on a flowering time of 8 weeks (average flowering time for a indica) then you would be looking at 11 – 12 weeks.

I think this section is the do or die between having a great auto crop or a disaster. Autoflowers have such a short vegetative growth period and the final plant is rarely very big. Get it wrong and you’ll end up with a lollipop stick of bud. That’s why I think that whilst autos fulfil a gap in the outdoor growers repertoire (after all its damnedably difficult to control the light/dark cycle of the sun), if you can its best to start them off indoors under lights. You just maximise the level of control that way.

“Once you pop ’em you can’t stop ’em”

Effectively this means that whilst the answer is “yes”, the autos have a genetically limited life: from the moment the cannabis seed germinates it will progress through its short vegetative stage and speed onto flowering. As the “mother” plant won’t be big enough to take a clone until she is around 5 weeks old, once you have added a week whilst the clone roots, the clone thinks of itself as 6 weeks old and upward vegetative growth will have finished. Despite being tiny, the cutting will finish flowering at the same time as the mother more or less – here’s one I tried for a laugh:

guide to autoflowers

Start off with a little veg feed at around week 2 and slowly increase the amount of feed as the plant develops up to (depending on the auto) around week 6 or even 7. Wait to switch to flower food until after the cannabis plant has noticeably stopped its upward growth, even though she may have been flowering for a week or so beforehand.

You can grow autos on 24/0 but I think its good to let them have a little rest time and electric consumption is also a issue. I grow mine for the first two weeks under a 120 watt draw Fero LED for the first couple of weeks and I tend to keep that on for 21/3 with the LED grow light around 70 -80 cm away from the seedlings. When then they are potted on to the 13 cm sexing pots and put under my larger LEDs I then change the lighting schedule to 18/6 where it will remain until I crop.

Yes you can but it needs to be in the very early stages as it holds the plant back in that critical time. I’ve experimented over several crops with this and my advice would be that you are better off not pruning autoflowering marijuana as in most cases the plant will end up giving less weight. That said, you can break the apical dominance and encourage vigorous side branching by “knuckling” if you are using a longer term variety such as the “Cream Caramel” (yes Sweet Seeds, I know you say this is an 8-weeker, but every one I’ve grown has gone to 12 weeks plus).

Lets assume your environmentals are all good, with light at around 400watts a m2, temps at around 23ºc, humidity 55% for flowering and you are replenishing your air every couple of minutes whilst maintaining a good nutrient regime and getting plenty of O2 to the roots etc etc (who ever said growing great smoke was easy?)

The simple answer is : it depends on how long the plants are going to take. The 3-monthly varieties such as MI5 (Shortstuff) average around 40g a plant (dried weight) under my fero led lights at 10 per m2 and the longer super varieties such as Chase (15 weeks) 150g -500g a plant outdoors.


Thanks! A perfect example of what I was saying about getting help here!


You’re welcome, sorry my phone has been shut off, so I reply as often as I can my friend

I feel ya! Life happens and we all try to keep up! Lol

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Majik…let me know if you are half way around the world or sometime for time oK?
I am northern ca and put this plant in the ground march 21 st outside… its growing rather nice colas and this is week eight now. approximately two feet tall, I bought it as a clone but due to the rapid budding I just assumed it was an auto.
thank you for your advice…

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Hope this helps but my buddy @Majiktoker got ya covered.

Simple grow guide for growing auto-flowering plants in soil

by Santacabrera

Auto-flowering cannabis plants growing in a tent using Santacabrera’s simple soil guideThis simple guide to growing autos indoors uses…

BioBizz Lightmix Soil
11-liter (3 gallon) pots
Adjustable digital 600W HID grow light (Learn how to set up your exhaust)
pH/PPM meter or pH Test Kit
Nutrients & Supplements

Advanced Nutrients pH Perfect (Grow, Micro & Bloom) as the base nutrients
Voodoo Juice (optional)
Overdrive (optional)
B52 additive (optional)
Plant Magic Evolution Spray (optional)
Big Bud (optional)
Blackstrap Molasses (optional)
Here’s what that all looks like together

Complete Nutrient system for growing auto-flowering cannabis plants in soil indoors

Extra Growing Tips for Autos

Low to Medium Nutrient Needs

Whether you grow in soil, coco coir, or a full hydroponic setups, auto plants tend to prefer relatively low levels of nutrients compared to many other cannabis strains.

When it comes to adding extra bottled nutrients, start at ¼ strength of the recommended dose or less, and only add higher levels of nutrients if needed. In hydro use “vegetative” nutrients until you see the first signs of flowering (pistils / white hairs) around 3-4 weeks. In good soil, you don’t need to add any nutrients during the vegetative stage. After the first signs of buds, start adding “flowering” nutrients at very low strength (¼ or less to start)

Potted Auto Plants

Potted auto plants tend to do best in an airy potting mix with lots of drainage (plenty of drainage holes, and something like perlite to help add more drainage to your growing medium). This helps makes sure roots get plenty of oxygen so plants grow as fast as possible.

If growing in soil avoid choosing a “hot” (lots of nutrients) soil mix. BioBizz Lightmix soil or Fox Farms Happy Frog are good choices that don’t have too many nutrients to start. With any soil mix, it’s recommended to add about 30% extra perlite for increased drainage.

Read more about a simple soil grow guide for autos

How I use coco coir to get faster growth than soil

Size & How to Control Height of Auto-Flowering Plants

The final size of your auto plants is largely dependent on the strain you get. Some strains, such as Lowryders, have been bred to grow extremely short - less than 1-2 feet. Other strains can grow taller, up to 4 feet tall or even more.

As a general rule of thumb, auto plants tend to double or triple in size from when they first start showing signs of flowering/budding (usually when plants are about 3 weeks old from seed).

There are also some plant training methods that are effective for giving you more control over the final size and shape of your auto-flowering plants.

The most important thing to remember with autos is to avoid using any plant training method that involves cutting the plant. When reading about cannabis training techniques that involve cutting the plant such as topping, FIMing, or main-lining, please remember that these techniques were developed for photoperiod plants are are not well-suited to auto-flowering strains.

Instead, the best way to control height and size with autos is to use low stress training (LST) which involves bending tall branches and using gardening wire or soft ties to hold down the branches.

Here’s a great LST example by Santacabrera showing how to gently bend the middle colas of an auto-flowering plant down and away from the center without cutting or harming the plant.

How to LST an auto-flowering plant picture by Santacabrera
Bend too-tall branches down and away from the center of your plant

When growers LST auto-flowering strains of cannabis, the general idea is to gently pull branches away from the middle of the plant, so that the plant looks like a star when viewed from above. This helps expose the lower branches to more light, while also keeping plants short. It’s important to only bend stems that are young, when they’re still soft and flesible. Older stems become woody and hard to bend.

This technique can be used on auto plants that are getting too tall for your setup, or for any stem that is growing taller than all the others. Most indoor growers want to keep a flat, even canopy when growing indoors to get the most from their grow lights.

Best Light Schedule For Autos

Most indoor growers report getting great growth rates when keeping light schedules on an 18/6 light schedule (18 hour of light and 6 hours of dark each days). 20/4 is another popular light schedule for indoor auto plants. Some growers will give 24 hours of light to auto plants, but others believe that auto plants develop better when given at least a few hour of darkness each day.

When growing autos outdoors, basically you just want to give your plants as much direct sunlight as you can each day. Other than that, you don’t need to worry about light schedules When growing outdoors, more hours of direct sunlight = bigger yields. It is almost impossible to give plants too much light when growing outdoors (as long as heat is under control).

B Safe


thanks so much. time to go back to school and get a science degree. but wait at 70 years I will jus go to school here. I have it in a ten gallon felt pot. I also purchased big bloom, tiger bloom and grow big. so, time will tell…


I live In central Arizona a 5 hour drive from central California 2 hour drive to get to blythe from where I’m at, I’m an 8 hour drive from northern California…personally one of my favorite road trip places, and a great drive, why what’s up buddy

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didn’t want to mess with someones "alerts on phones if they are half way around the world…

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I have been guilty of calling our girls “just a weed”. But my outlook on weeds is different than most people.

I will often let my yard get overgrown just so the weeds can come up. Most of our weeds that are mowed down have many benefits.

Blooming weeds will attract pollinators for the vegetable garden, most weeds have some kind of health benefits. They can enrich the soil if not allowed to take over. Many other reasons IMO.

Personally, I don’t like a grass lawn. It can look pretty when properly cared for, but the manicured lawns, combined with over farming our lands has contributed greatly to the poor water quality that many people have to contend with.

Hmm…I just realized that for me, lawn grass is nothing but a damned weed! LMAO


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It’s because the grass of the field is for the cattle. Their stomachs (noticing it’s plural) are able to process it enough to get the nutrients.

Thistle is a fantastic diuretic. Didn’t know that until I was researching my gout issues. I always figured it was meant for us because I don’t know of anything in the field that eats it!

If I can get my gardening down, I plan on turning most of my property into a food and herbal remedy plot. Damn the grass! I don’t have cattle! Lol

Sorry for hijacking this thread. Sometimes the mind goes wherever it wants.

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Got ya yea I’m pretty close lol

Yes, aren’t fertilizers responsible for the “dead zone” located at the mouth of the Mississippi ?


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Hoo! I guess you could say our passion for growing medical marijuana can be good for the planet. I have also learned much about how little plants need. Thanks to @ latewood I’m seeing the healthiest plants ever and only giving them 1/4 the nutes I used to.