Anyone grow autos under 12/12 for whole grow?

I know it’s kind of unusual to do this but I wanted to minimize wait time between harvests by alternating a crop of photoperiods and a crop of autos because I only have one room light-proofed. So my plan was to start a crop of autos while the photos are finishing up flower… Has anyone grown autos under 12/12 for the plants entire life? How significant would the yield difference be? Or maybe once I harvest the photos I could give the autos more light… Any experienced auto growers have an opinion on this??

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I have a few times. It will grow just fine but severely lack density. The buds will ripen just fine but will be airy and fluffy.

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I have a friend that starts her autos in with her flowering photos on a 12/12 and once the photos finish she’ll flower the autos in with the next vegging photos on a 18/6 schedule

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@MeEasy thats actually not a bad idea

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She says she’ll start the autos when the photos are about half way there and the timing works out pretty good

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I think thats exactly the kind of thing I wanna do. Is your friend on this site? Could you link her if so?

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I guess I’m not attempting it. I already started :laughing:. Trial and error… Just figured I would ask around while in the middle of the process haha typical stoney me…
There’s are purple haze autos I started a little bit ago…



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No she’s not on here she’s an old neighbor

They look happy n healthy

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I don’t grow autos at all, but that has no bearing on the context of your question. You can grow autos or photos on 12/12 from start. They will not flower right away even if you only had 4 hours of light. Both autos and photos will have to mature before they will flower, expect this to take 4-6 weeks if everything goes well.

The development of your plant over that period will depend on environmental conditions. The process used to explain light energy over time is called daily light integral. Basically the light intensity plant canopy gets by amount of time it’s there. So a ppfd average of 400 umols/s for 18 hours is exactly the same dli as having a ppfd average of 600 umols/s for 12 hours. If all other variables are the same, the plants process exactly the same amount of energy.

In short, there’s nothing wrong with running autos or photos on 12/12 start to finish. If you don’t have strong enough lights to hit dli peaks, then your plants won’t be as big or produce as much. If you can peak dli, then it doesn’t matter if you have more light or run your lights indefinitely, without adding more co2 your plants will have reached energy saturation.

Remember that Individual results are going to have Individual variables. Someone with great setup may crush a grow using identical methods that someone else failed miserably with. Doesn’t mean the method was wrong or bad. Execution could be stellar or miserable, or could be large gap in performance of equipment being used. In terms of will or won’t work, you’re plenty good to do this. How well it works out will depend on how well your grow is maintained.

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I grow 12/12 start to finish. Autos and Photos. My theory is it hurts how much weight you will get. They always smoked great.

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Thanks so much for the input. Ive been watching Dr. Bruce Bugby’s vids and doing other research about lighting so I have an inkling as to what you’re talking about when it comes to micromoles and the DLI. Thanks again bro

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Oh thanks anyway man. Sometimes thats where the best knowledge comes from lol

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I’m goona put them in here for now, temporarily. My ppfd meter is a cheap one with built in moisture and ph meter so I’m guessing my cheap lights aren’t actually pushing over 2000 umols like the gauge says haha too good to be true.

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Like @dbrn32 said. It’s a very grower dependent variable. But I’ve seen journals with photoperiods 12/12 beginning to end that finish faster/larger/appear denser than autos.

Personally I’ve found as I actually get all parameters dialed in I have plants quadrupling in height after flip (change to 12/12)

Point being. If you want to get all parameters dialed in… you may aswell grow photos starting 12/12. The ruderalis gene doesn’t help any beyond the auto feature. This will always be a crutch in auto strains.

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Ya know thats a really good point. Ive also heard the ruderalis in nature is much less potent, and making my own conjecture, I would assume that any auto is probably producing slightly lower cannabinoid levels than its photoperiods counterpart… Well I have the seeds now so gotta use them… I wonder how it would go if you top photoperiods grown under 12/12…

As I mentioned. You’ll find people here that grow photos 12/12 beginning to end. I just really really suck with names… part of my head I never got back from bad decisions.

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This makes a lot of sense now, I didnt even think about folks who grow outdoors near the equator. They get some 8ft trees down there and that’s 12/12 the entire time… Very intriguing.

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Thanks man I’ll look around. If you remember in the mean time could you give me names or tag them here?

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@dbrn32 hey I believe you’re quite knowledgeable with lighting… Do you know of an accurate ppfd gauge for a low ptice. I know apogee has amazing instruments but I can’t afford them lol

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