When to top autos

I’m just wondering when the best time to top autos are? I’ve heard some people on this forum get as much as 10oz per plant and I plan to top all my autos that I just started a couple weeks ago.

I top mine at the 4th or 5th node. You do this only if you have at least 5 nodes by about 14 days from sprout. I get 10+ oz from one auto


I’ve had luck with topping the 4th node the moment it shows its head. Only if before day 21.

I only get about 6oz, but hornhead is a much better grow than me, from the start.


Thank you both for the advice. I should have 3-4 outta six that fit those categories.

I have another couple questions for @blackthumbbetty & @hornhead. What light schedules and nutrients do you use? Again, I’m new and would love to soak up as much knowledge as possible from you both.

Thank you :pray:

I wouldn’t say better. I’ve just grown all 25 wwa and know how they are @VTGROW I use the general hydroponics flora trio Lucas formula about 3/4 strength. I run my light 24/0 first week or two, then 16/8 until I see flowers, then 12/12


I usually run a similar light cycle…but instead of 16/8, I do 18/6, then don’t start 12/12 until they’re in full bloom. I run organics (Earth Juice, other organic nutes, and microbes) and love them.

And, yep, I rarely run the same strain twice. Still, accept the praise, you pothead @HornHead. :grinning:

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Hope you don’t mind me joining. Is topping should be done for indoor only or outdoor as well? I grow outdoor and didn’t top nor trim as I’m too afraid I’d damage the plants not knowing what to do. And if the plant was never topped when it was young, would it do anything to top when they are full grown but not flowering yet? thanks!

Topping or fimming is a technique that should be used on all your plants, photos you can top multiple times. 2-3, but as I’ve never run autos I’m not familiar with that subject.

I prefer a fim over a top just for the recovery time. It’s all preference with the same results

I don’t recommend topping autos until you’ve grown a few of them and get a feel for their life cycles. It’s very easy to stunt an auto when high stress training is applied at the wrong time. For autos, if you are going to attempt topping, you need to do it when they are young.


@blackthumbbetty @HornHead why do you guys switch to a 12/12 during flower and not keep your 16/8 or 18/6 schedule? Have you ever kept the 16/8 or 18/6 through out the entire grow and have the results been beter switching to the 12/12? My grow right now I’m going with 18/6 throughout the entire grow and seem to be doing well. Thanx for any info!

I’ve tried blooming autos at 18/6 16/8 and 12/12. I get same results either way. 12/12, I save on electricity @WickedAle runs autos 12/12 from seed


I have. I saw no benefit from it, personally. If your lights are giving your plants the right ppfd, there’s plenty of light at 12/12; weak lights might benefit from longer light hours. I switch to 12/12 to save $.

I have grown autos 12/12 from seed, as well, without any issues.


Happy ILGM Anniversary @HornHead :blush::confetti_ball:


Thank you all for the great info. I will try to use those light schedules to save $$$ too as long as I can control temp and humidity.

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you have forgot the ph levels of the soil , between 6-7 buy the way ,got reader on e-bey for a fiver

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@blackthumbbetty,@hornhead If I understand you correctly in what you are saying is that under no circumstance should a auto be topped or trimmed past the plant existing for 21 days.

I don’t think you should top autos until you’ve grown them a lot, and even then I truly don’t recommend it, unless you’re feeling lucky.

LST works infinitely more reliably and safely.


@blackthumbbetty, What about trimming shade leaves to open up the canopy .

@Killadruid could probably help ya with this.

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