General autoflower questions

Hello, I’ve just started considering growing my own, and this have been reading and viewing videos on beginning growing and tent grows, but I’ve got some very basic questions about Autoflowering seeds.

Everything I’ve seen says that autoflowering plants will start flowering without regard to how much light they receive per day, but not much else. But is changing the program for lighting, when plants are ready to flower really that big a deal?

Some things mention they ares a bit faster growing, but don’t really say anything more, so that raises the question, is it faster enough to really make a difference, and are their drawbacks to the faster grow time, since as I understand it, the longer the plant is healthily growing, the better and stronger the buds will be.

Finally, I guess really I’m just looking for a pros and cons list for autoflowering vs non, as if it’s just saved me from having to change the light schedule, and shortens grow time by a week or two, but if I end up with less and/or weaker buds, I’ll gladly reset the timer for the lights

Thank you


Welcome @StarKiller
I started growing a year ago and have grown only autos. My main benefit is that I do not have to worry about power outages throwing the schedule off. I live where summer storms are a near certainty.
Also, I can set lights at 18/6 and leave it while growing plants in different stages of growth for a “perpetual harvest”. I try to have 3 plants going at all times with 5 or 6 weeks between each and start a new one just as the most mature is getting close.


I’ve only been growing for a month. This is my understanding & others can correct me if I’m wrong.

The “auto” in autoflower is that they are crossbred with C. ruderalis. C. ruderalis are native to cold, northern climates and don’t depend upon daylight to switch to flowering. You can run your auto flowers on 24-0 or 12-12 and it won’t affect when they decide to bloom. It will, however, determine how much stretch you get in vege.

Photos won’t bloom unless they receive at least 12 hours of dark. If you have a photo you really like, you can take cuttings and grow clones of it for years while you keep it in vege.

Personally, I have three autos and one photo going. My plan is to keep my lights on 20-4 until I harvest the autos. Then I’ll decide if I want to bloom the photo right away or keep it growing some more before switching to 12-12.

Ruderalis varieties tends to be the smaller of the three species, so autos also tend to be smaller than photos. Combine that with the automatic blooming cycle and that means a smaller harvest than with photos.

The benefit of growing autos over photos are:

  • generally easier to grow
  • ready to harvest faster
  • you can get away with smaller pots
  • you can get away with less than ideal lighting

The benefit of growing photos over autos are:

  • more control
  • greater variety of growing techniques
  • bigger plants
  • bigger harvest
  • cloning mothers instead of buying seeds

Oh, you know I hadn’t considered being able to stagger harvesting in that manner, thank you very much.

I knew there had to be something I was missing, but couldn’t figure out what. I also hadn’t considered power outages, although they are fairly uncommon here, Western NY, and when they do occur they usually don’t last more than a few hours, as I live near one of the main lines between local towns, so unless power is out over a wide area, the main line is normally a very high priority. But, with that being the case, would a power outages, if say 6 hours, have a large effect on a grow that wasn’t using auto flowering seeds?

Along that same lines, they stress the time with the lights off being completely pitch black, which makes me wonder how outdoor grows handle it, as a significant percentage of nights have a fairly bright sky?

Thanks again.

Yeah, cloning was the main reason I was more interested in non-auto flowering, because seeds themselves can be fairly pricey, so each successful clone would basically save me $5-10, or more, in seed purchases.

Although, as I said I’ve only started reading upon growing in the last few days, so I’m sort of clueless at this point, and have a ton to learn.

Thanks to both of you for your responses.

One last question, what would be the difference between two plants of the same strain, one autoflower and one not, assuming everything went perfect in every stage of their growth? How much faster would the autoflower be ready, would either likely have noticeably different THC/CBD percentages than the other and/or significantly higher yields (also, when it comes to higher yields, are we talking 5-10% difference or 20-30% or even larger variation?)

Sorry for all the questions.

Merry Christmas and/or Happy Holidays to you both (and every other forum member.)

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Mainly would come down to how you grow the photo period plant and how long you veg it for. The auto will make it’s own timeline so you are at it’s mercy as far as veg.

If you flip the photo to flower at the same time as the auto, they would finish nearly the same.

All things being equal, I don’t think there is a huge difference. Growing a photo to be larger will of course result in greater yield.

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One thing about autos is they are a poor choice (in general) for training. Anything you do can stunt them and they never catch up. If you have a problem with a photo you rectify then veg a bit longer. Potency used to be lower in autos due to the Ruderalis but not so much any more.

There are some growers here who have the touch when it comes to autos: @Not2SureYet is top of my list.

I actually think pointing new growers toward autos is a mistake as photoperiod lets you get away with some issues, which you’ll always have.


First welcome to the community.

Autos can be on 12/12 to 24/0 but like all living things, they also need a rest period. So many will grow them on 18/6. They do what they want, when they want. You have no control like you do with Photos.

Autos if you have a problem, you really don’t have time to correct it. Especially if its bad.

My newest photo broke surface on 11-11-2021 and I just took this photo on Saturday aka almost 1 week ago. She is already flowered.

Personally it would be better for a new grower to try Photos first as Autos can be a extreme pain in the rear.


Welcome to the community auto plants definitely have a spot in the cannabis growing world. They usually start flowering between 4 to 7 weeks and seed to chop about 10 to 14 weeks depending on strain. There are several auto growers Active in the community. @Nicky @OGIncognito


I have a white widow CBD auto going right now. This is it’s cut sheet. 10 - 14 weeks to harvest.

For the photo version, it’s 9 weeks to flower.

Also an indicator for grow rate, these are my crops, they are different varieties but all the same age. The small, upper right one is the photo. But it has also been topped and I’ve taken it’s three largest leaves off.


I should also say, that the 3 autos won’t get more than 2 - 3 tall even without training.

The photo will out grow my tent unless I aggressively high stress train it. I might harvest more off it than the three autos combined.

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I grew photo period plants for a couple of years before I made the switch to autos. There were a few reasons, but the number one was always avoiding light leaks. I had a tough time getting enough air flow in and out because I had everything sealed up so damn tight everywhere. Once I started growing autos, I ditched all the S turns in my duct work, and just keep the lower ports on my tents wide open (with filters over them for cat hair, lol.)


Here is one of my Autos. It grew exactly this way.

Now this was a small Photo I grew.


Thank you to everyone who has responded, I really appreciate your help.


The pros with auto flowers they grow quickly and there easy to grow they flower quickly less waiting time and i dont need to change light cycles for flowering unlike photoperiod plants ,cons of auto flowers is if u get a deficiency or do training they don’t have much time for recovery you can’t veg them out longer like photoperiod plants

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So here’s my two cents. I’ve grown both, but mainly photos. I rarely ever have any issues with photos, but I have had issues with autos. My buddy gifted me a banana kush auto seedling from ILGM. I’m getting ready to harvest today. It’s not been a very good plant. It’s had brown spots on leaves since it started flowering, and I’ve tried everything I know, and I’m not a new grower. Just seems to me photos are more grower friendly. Here’s my banana kush coming down as soon as I finish typing this.


I have had pretty good luck with autos. The above pic is a 54 inch tall Super Lemon Haze auto from ILGM. I grew out 4 of them and yielded just over 1lb. 3oz.from the 4 autos. Next pic is the full tent with my tomato plants in pots also.


Thank you to everyone who has responded, I guess I’ll try a couple of each and see how it goes.

As things sit now, I’m planning on a 4x4 grow tent, so maybe I’ll start two auto and two photo, with the idea being that I’ll harvest the autos much earlier than the photos, thus hopefully not only getting a little of my own stuff sooner, but also giving me a little experience with each type (although I understand and accept that my first grow will be far from magazine cover worthy.) :rofl:

If I go that route, would everyone suggest I did 4 plants of the same strain, 2 auto and 2 photo, so 2 seed types or would you suggest I do two different strains (either 2 seed types with the auto being different from the photo, or 4 seed types doing an auto and a photo of each strain?)

Thanks again.

I wrote this response a couple hours ago, but I ran out of responses, as I had only signed up to the forum last night, so I had to wait a few hours to hit Enter. :joy:


If your plan is to mix things up and going to run autos and photos together, I would see no need to keep the two strains the same unless you are trying to do a comparison between autos and photos of the same strain. No matter what strains of Autos you do compared to photos they will grow differently. They may also require a different nutrient schedule. I have grown autos and photos in the same tent on several occasions, I have noticed that if I can keep autos on a 16/8 schedule they seem to produce more and heavier flower. With my lighting 18 six is too much light and it stresses them out and causes severe calmag issues. The Autos will still produce decent under 12/12 lighting and will be under much less lighting stress if you’re running high intensity LEDs but don’t expect as much yield as you will get from your photo plants.
I am currently growing 2 autos, two photos, and one clone photo that will all be in the same tent running under the same lighting schedule and I’m hoping the autos flower soon and I can run a 16-8 light schedule at least partly into flower before I have to flip the photo plants.


:laughing: Sorry had to :wink: And welcome to the forum SK. This is the best advise I could give. Autos can be very easy to grow. I wouldn’t do one unless in coco. You have a lot more control than in soil. @Myfriendis410 saw my first grow. 4 autos that barely fit in a 3x3 and a 4x4 tent. 23 1/2 oz total. And I did about every thing you could do and still made it through. You can keep autos shorter with training. I would never recommend more than 2 of either in a 4x4 for your first grow. I could show dozens of pictures why not. Especially with autos. You can get the odd small one. Or get one that wants to grow big.
One thing I think gets over looked is. If you fill a tent. Doesn’t matter what size tent. Your humidity is going to go way up in flower. And make it a little more difficult to control the humidity. After a couple grows. You will figure out what works best for you :grin:
So, my advise is. If you want to do any autos. I would look for some one to help you through the whole grow. That will mean listening to them when they advise you to do some thing.
The only reason I did good with my first grow was @Myfriendis410 and @MattyBear were my mentors. When they said to do some thing. I did it and then asked why. My thoughts are that if you are going to ask a specific person for help. You should be listening. As mentioned. There are a lot of great auto growers in here. While there is more wiggle room for errors with photos. I still prefer autos. If you get the start to 10 day period down. The rest is easy