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Auto flower question

Wilky

Member
I’ve had 2 Auto flower plants growing under 18/6 light schedule.
Just after 4 weeks I changed cycle to 12/12.
Have I done the right thing? Or should I have left them on 18/6?
My last grow I had Auto flower seeds, well thats what I ordered, but they kept growing. Someone suggested dropping to 12/12 and they started to flower.
But Ive been reading some posts and most say leave on 18/6 all the time, which I see why ‘Auto flower’ term is used, but I dont want to run the risk of these not actually being Autos.
Should I leave 12/12?, its been a week.
Put them back on 18/6?
Anyone got the best advise who may have come across this?
 

Wilky

Member
Leave them at 18/6. They do better with the longer light schedule.if they truly are Autoflowering the schedule doesn’t need to drop. Some will run 20/4 from start to finish.
What are consequences of leaving them on 12/12?
Incase they aren’t.
Last time as a result they didn’t bloom until I changed. That was 6 months on a 20/4 cycle!
 

Hydroholic

Well-Known Member
What are consequences of leaving them on 12/12?
Incase they aren’t.
Last time as a result they didn’t bloom until I changed. That was 6 months on a 20/4 cycle!
Less time under lights will effect growth. Autos have a short flower time and being on 12/12 is going to effect weight for sure. If an auto doesn’t flower by week 6 I would question if it’s an auto or not. Autos are meant to grow from start to finish with 18+ hours of light because of the short growth time.
 

Nunyabiz

Well-Known Member
The only reason to even grow an autoflower is because you can keep them at 20/4 through flower.
Dropping to 12/12 will just cut your yield in half.
Light cycle should be a minimum of 18/6, 20/4 is best for most cultivars.
More light, more growth.

Here's my little autoflower that is 29 days from planting the seed.
It's a little over 35" tall and looks like will have 15 buds.
That's an average of about 1.25" of growth everyday for 29 days.

20190912_100050.jpg
 
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Wilky

Member
Thought about that but I feel they need some time to ‘rest’ and also cuts down on Electric bill
 

flashmp3

Plant of the Month: Nov 2019
The only reason to even grow an autoflower is because you can keep them at 20/4 through flower.
Dropping to 12/12 will just cut your yield in half.
Light cycle should be a minimum of 18/6, 20/4 is best for most cultivars.
More light, more growth.

Here's my little autoflower that is 29 days from planting the seed.
It's a little over 35" tall and looks like will have 15 buds.
That's an average of about 1.25" of growth everyday for 29 days.

20190912_100050.jpg

I was repeating things I had read on internet regarding autos until I try to grow an amnesia XXL auto outdoor this summer along with 2 green crack auto. They were germinated indoor and spent their first 2 Week from sprout indoor under 20/4. Then I moved them outdoor. They could receive only a maximum of 8 hours of direct Light. I never saw plants growing that well. Over 200g dry for each plant. All this to say that this experience made me realize maybe some stuff were said about autos by a lot of people (including me in the past) that didn't really make the experience themselves. I mentioned your post as it could have been any other one as multiple people say the same. I don't understand how I could get such plants with only 8 hours max of direct sunlight. Today I m pretty convinced flowering an auto under 12/12 don't impact yields at all. But I could never find any side by side test. So I prefer not saying anymore than autos need at least 18/6. I know outdoor is different but I also know my indoor green crack I decided to put under 15/9 is doing way better than the first one that was under 20/4. In fact the one that received the longer lights period is the one that yield and develop the least out of 5 plants. Anyway just wanted to share here as I believe some experts should take time doing side by side tests




And those plants suffer from different trouble. My dog ate one of the 4 main branches, they had too much bacterias in the coco for the first days etc... Maybe some strains need more lights but as you can see amnesia XXL auto and green crack auto seem to do wonders with only 8 hours. I got mold in all the 3 main and biggest buds. Even with that it was over 230g. I don't see how she could produce more... Green crack over 200g as well. I hope you understand my point guys. I was the first to be surprised but it's facts...
 

Hydroholic

Well-Known Member
I was repeating things I had read on internet regarding autos until I try to grow an amnesia XXL auto outdoor this summer along with 2 green crack auto. They were germinated indoor and spent their first 2 Week from sprout indoor under 20/4. Then I moved them outdoor. They could receive only a maximum of 8 hours of direct Light. I never saw plants growing that well. Over 200g dry for each plant. All this to say that this experience made me realize maybe some stuff were said about autos by a lot of people (including me in the past) that didn't really make the experience themselves. I mentioned your post as it could have been any other one as multiple people say the same. I don't understand how I could get such plants with only 8 hours max of direct sunlight. Today I m pretty convinced flowering an auto under 12/12 don't impact yields at all. But I could never find any side by side test. So I prefer not saying anymore than autos need at least 18/6. I know outdoor is different but I also know my indoor green crack I decided to put under 15/9 is doing way better than the first one that was under 20/4. In fact the one that received the longer lights period is the one that yield and develop the least out of 5 plants. Anyway just wanted to share here as I believe some experts should take time doing side by side tests




And those plants suffer from different trouble. My dog ate one of the 4 main branches, they had too much bacterias in the coco for the first days etc... Maybe some strains need more lights but as you can see amnesia XXL auto and green crack auto seem to do wonders with only 8 hours. I got mold in all the 3 main and biggest buds. Even with that it was over 230g. I don't see how she could produce more... Green crack over 200g as well. I hope you understand my point guys. I was the first to be surprised but it's facts...

Amnesia xxl says 100-250 grams outside. Your within the size for outdoors. Knowing how a plant breaks down nutrients using light will tell you enough that the more nutrients we give a plant the more light it needs to turn these into food. You are not getting everything out of a plant at 8 hours . 8 hours of light is right on the edge of what a Cannabis plant needs just to survive . The rubella plant that autos are crossed with see 24 hours of light so even the genetics are meant for the extended light. I have also found many articles on testing with light cycles of Autos that show that 20/4 and 18/6 are best suited for Autos because it gives enough light and enough dark time for photosynthesis.
 

Nunyabiz

Well-Known Member
Everything I've read including from the breeders and seed producers all state that 18/6 to 20/4 is best cycle for overall yield, density of the bud.
I can only assume these test have been done.
Logically since the Ruderalis natural climate is up to 24 hours of light you would think that 12 hours or less light is less than optimum.

All I know is the few autoflowers I've grown seem to flourish under 20/4.
My current one is flourishing a bit too much as the last 3 days it has grown 4" per every 24 hours.
I am going to have to LST it today I think to control it.

Here it was 7 days ago.
20190908_001003.jpg


Here it is this morning.
Its grown 26" in 7 days which is an average of 3.7" per day for 7 days.
It would be interesting to have grown the same strain side by side at 12/12 just to see but I don't have the space or time or equipment to do that.
I would guess that it would be growing about 2" per day instead of 4" but once the buds start to fatten I think is when the biggest difference would be seen.
Light/photons are literally what feeds the plant.
In your case iam going to guess that for the 8 hours or so of light they received that it was strong sunlight, intense light.
Therefore it probably got close to what it would have gotten indoor for 18 hours under a light putting out like 300PPF .
So your DLI (Daily Light Integral) was probably close to the same as a low output light for much longer light cycle.

Now if you were to grow that same plant under a very intense LED putting out 800-900 PPF for 18 to 20 hours then I can virtually guarantee that plant would produce more bigger denser buds than one growing 8 hours outside.
The DLI would be considerably higher so as long as the plant has the food and water to utilize that much light then it's going to grow accordingly.

I also believe the longer a plant especially one with thick buds remains in total darkness the greater the odds of it getting some form of mold or pathogen to cause bud rot.
I much prefer 20 hours of intense light so that I can better keep my environment exactly dialed in with proper VPD with as few fluctuations as possible.

20190915_110940.jpg
 
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flashmp3

Plant of the Month: Nov 2019
Amnesia xxl says 100-250 grams outside. Your within the size for outdoors. Knowing how a plant breaks down nutrients using light will tell you enough that the more nutrients we give a plant the more light it needs to turn these into food. You are not getting everything out of a plant at 8 hours . 8 hours of light is right on the edge of what a Cannabis plant needs just to survive . The rubella plant that autos are crossed with see 24 hours of light so even the genetics are meant for the extended light. I have also found many articles on testing with light cycles of Autos that show that 20/4 and 18/6 are best suited for Autos because it gives enough light and enough dark time for photosynthesis.

Regarding the size of the amnesia, and the yields (maximum of what advised my the breeder) I don't see how she could have got bigger honestly. Maybe the pics don't show how big she was. Same for the bigger green crack. 200g for a plant of this size is great. I don't think she would have produces 250g indoor but I don't know. What I know is that with what you call the minimum to survive, I got outstanding plants. Like you I was thinking of poor yield and was ready for it. I just wasn't ready to see monsters like that and this with many mistakes during veg period which is so crucial for autos. I don't want to debate as I m no expert. I m just reporting things I saw in my garden and I felt like I needed to share it to encourage growers to choose auto for summer grows even if they don't have the 12 hours of recommanded outdoor sunlight to produce decent. When I look at all the journals of same strains on grow diaries website for example, I don't see any plants only one green crack, that produced and developed that well. So I think mother nature's sun has more than we may be thinking. If I had come here saying I get more than 200g dry of outdoor autos under 8 hours of direct sunlight, I don't think many people would have believed it... Including myself at first..... I m still waiting to see comparative grows cause I never could find a single one on the internet. It s like we can only rely on what the breeders write
 

423

Well-Known Member
I'm pretty sure light cycles can still have a bigger impact on auto's than what seems to be accepted. Ok
I've had some "Dutch powerplant Auto" that were taking a long time to finish, and cutting light time seemed to encourage the plant to finish more as quickly.

Just from my limited experience I think many auto's would finish faster under less light time, and likely take longer with an increased light period but with a higher yeild.
 

Len Goodman

Well-Known Member
Regarding the size of the amnesia, and the yields (maximum of what advised my the breeder) I don't see how she could have got bigger honestly. Maybe the pics don't show how big she was. Same for the bigger green crack. 200g for a plant of this size is great. I don't think she would have produces 250g indoor but I don't know. What I know is that with what you call the minimum to survive, I got outstanding plants. Like you I was thinking of poor yield and was ready for it. I just wasn't ready to see monsters like that and this with many mistakes during veg period which is so crucial for autos. I don't want to debate as I m no expert. I m just reporting things I saw in my garden and I felt like I needed to share it to encourage growers to choose auto for summer grows even if they don't have the 12 hours of recommanded outdoor sunlight to produce decent. When I look at all the journals of same strains on grow diaries website for example, I don't see any plants only one green crack, that produced and developed that well. So I think mother nature's sun has more than we may be thinking. If I had come here saying I get more than 200g dry of outdoor autos under 8 hours of direct sunlight, I don't think many people would have believed it... Including myself at first..... I m still waiting to see comparative grows cause I never could find a single one on the internet. It s like we can only rely on what the breeders write
And there is a lot of misinformation as well. People read what other people did and spread it as fact, that’s why you can’t get proper help. I see everyone it’s your PH check it. It’s like the go to answer to fixing lol. Well I tried a plant with the assistance of the internet and I had one sitting in water locked out waiting for the environment to dry the bucket. I have also come up with a way for you to manipulate your auto flowers for bigger yield.
 

Hydroholic

Well-Known Member
Regarding the size of the amnesia, and the yields (maximum of what advised my the breeder) I don't see how she could have got bigger honestly. Maybe the pics don't show how big she was. Same for the bigger green crack. 200g for a plant of this size is great. I don't think she would have produces 250g indoor but I don't know. What I know is that with what you call the minimum to survive, I got outstanding plants. Like you I was thinking of poor yield and was ready for it. I just wasn't ready to see monsters like that and this with many mistakes during veg period which is so crucial for autos. I don't want to debate as I m no expert. I m just reporting things I saw in my garden and I felt like I needed to share it to encourage growers to choose auto for summer grows even if they don't have the 12 hours of recommanded outdoor sunlight to produce decent. When I look at all the journals of same strains on grow diaries website for example, I don't see any plants only one green crack, that produced and developed that well. So I think mother nature's sun has more than we may be thinking. If I had come here saying I get more than 200g dry of outdoor autos under 8 hours of direct sunlight, I don't think many people would have believed it... Including myself at first..... I m still waiting to see comparative grows cause I never could find a single one on the internet. It s like we can only rely on what the breeders write
The outdoor yields for autos is smaller than indoor. Why? You don’t get as long of light as you do indoors. So already your yield is showing smaller. To say you don’t know how they could have been bigger. Longer light creates more sugars that the plant uses for growth. Take away 1/2 of the light or food available and your yields go down. Not sure there is much life on earth that you feed less and it gets fatter. There are lots of books on photosynthesis that will explain. If growers could get max yield out of 8 hours of light they would. Kinda like cross breeding the rubella plant with cannabis.
 

Bud

Well-Known Member
Grown autos for a cupple of years now. First as a filler for my photos but I must admit that the quality
Of the strains has improved greatly over the past years, and records are being broken almost daily, for, yield, thc, & Cbd’s I’m just wondering what’s ahead for them ? We already got super autos ....
 
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