LST or risk top burn growing autos in short tent?

I have read the pros and cons of LST on auto-flowers. I think I would prefer to just let them grow with the least stress possible. However, my grow tent is only 69". Subtracting for the light, the platform on the base, and the pots, I have effectively 48" of growth space. Given I would like to be able to stay at 18" from the light if needed, that leaves 30" maximum plant height. If I just let them grow and they get taller than 30" I potentially have a major problem with burning the top colas (Damn! makes me cry just thinking about it). Otherwise, I can LST to minimize the height of the plants, but then I risk stressing the plants and reducing their overall growth. Anybody know how tall these varieties get?

Some additional information. I seeded two AK47s and two Jackpots. The total tent size is 3’ x 3’ x 69."


They have the potential to get taller but with lst should be able to control,however I have no knowledge on that strains


Listen to that guy! Do you have room for a SCROG grid? Pic’s of what you are working with would help

I have grown the AK47 auto and she didn’t get taller than 24” so that is a great candidate! :+1: and that was without any training

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So plants typically double in size during the transition to flower. I would just keep an eye on them and if they start getting too tall before transition then I would do some LST or supercropping.

@MattyBear It seems that AK47 auto doesn’t grow too tall, so hopefully I will be able to let it go.

@Ray4x I have heard that general rule. Your advice is right. I don’t need to decide now, but I can’t help but get ahead of myself. It is too exciting as first timer.

@Whodat66 This is the tent. The lights can go up about 24."

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So I’ve been thinking the same thing about autos and I’m going to try an auto grow with some lst , just bending the main stalk allowing the side branches to become main colas.

@Wishingilivedina420state I waffle back and forth between fimming and bending as you describe, but have been leaning your way towards bending.

One thing I didn’t mention that I see as another variable is optimal growth height. It seems it almost doesn’t matter the height of your tent. The light intensity quickly decreases with distance, so I am thinking optimum height is about 24" to 30." The drop in light intensity over three feet is pretty significant. It would seem at four or five feet you would be wasting almost half the plant and extending the overall grow time. I would be curious to know other peoples thoughts about this.

I am planning on doing autos back-to-back to get two quick grows in over the winter, but next fall I plan to do regular plants and SCROG a nice 32w" x 32d" x 28h" Christmas tree lot.

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I agree that an inside grow it waist the bottom of the plant it is that tall .
Witch is the reason I scrog , flat and even gets bigger fatter harder nugs hands down.

Topping or fimming autos is not a real good idea and i don’t suggest it for new growers. But it’s your plant and your call. I’m not telling you what to do, just suggesting. But with that being said there are pros that do it and get nice results. There are threads on this subject you’ll have to search it in the topics.

You can probably go with 12" distance with those LEDs. I go 14" with a 400 watt HPS and the top cola is fine. I vegged my Northern Lights non-auto until it was 21" and it stretched to 44", so you can do that without any training or SCROG. But I would SCROG just to get more even cola lighting.

Hurray! Number two is pressing up. I suspect she will pop out today.

@Wishingilivedina420state I know it is not recommended to mess with autos at all, which is why I lean that way. However, I have been reading about it and a lot of people have had success with both topping and LST. Including a first time grower here that got 84g out of one auto AK47. But as has been pointed out, I do not have to make that decision today. THANKS FOR YOUR INPUT!

@1BigFella I think you are right. The manufacturer suggests 12" and I believe I can likely get even slightly closer as someone else on here has pointed out. However, I don’t want to be forced to.

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This is the grow journal regarding the AK47 –<>– M4

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