When do I stop pinching tops?

[Simon Limon]

I've got two plants outside in soil, one each sativa and indica, and two indica inside a grow tunnel/greenhouse in big pots. The potted plants had some early LST but for the past couple of weeks I've left them without further training -- and they are going up fast. I'm continuing to pinch the tops on both the outside and inside plants but wonder when I should stop?

I'm at 45º N so the general word seems to be that they'll flower in mid-August.

What do you think?

 

[Simon Limon]

This photo shows the difference in height between the LST plants and the plants I've left off training. I pinched the tops again yesterday on the tall plants. Their rate of growth is impressive but when should I stop any form of training or pinching? This is my first grow so I have no idea.

 

[andIhalped]

I've got two plants outside in soil, one each sativa and indica, and two indica inside a grow tunnel/greenhouse in big pots. The potted plants had some early LST but for the past couple of weeks I've left them without further training -- and they are going up fast. I'm continuing to pinch the tops on both the outside and inside plants but wonder when I should stop?

I'm at 45º N so the general word seems to be that they'll flower in mid-August.

What do you think?

I usually stop at least two weeks before I figure they'll start flowering, to: a) let them recover from topping as they head towards flowering & b) avoid retarding the onset of flowering.

I'm at your latitude, just topped for the last time today, even though I might be 3 weeks away from flowering.

Yours are looking great, should have lots of bud sites...time to let 'em go.

 

[Simon Limon]

I usually stop at least two weeks before I figure they'll start flowering, to: a) let them recover from topping as they head towards flowering & b) avoid retarding the onset of flowering.

I'm at your latitude, just topped for the last time today, even though I might be 3 weeks away from flowering.

Yours are looking great, should have lots of bud sites...time to let 'em go.

I really appreciate your reply and advice. I have a related question about the plants I've been training. I didn't know about manifolds and quads when I began LST so I more or less re-invented the wheel and now have low sprawling plants with 2-5 big stems and many side shoots. I haven't done any pinching on those but wonder if I should stop bending stems and let them go up now?

 

[Pbass]

Nice plants Simon Limon they look beautiful! I think you can keep LST as long as you want, as you aren't really causing the plant to stop growing and split like a top, just telling it "why don't you grow over here", right? Thats my understanding of it anyway. Cheers mate, luck to your grow!

 

[bobrown14]

In those size pots the plants are going to grow tall.

Topping will at some point be counter productive. The plants need special hormones to promote flowering. Those hormones are at the tops or ends of the stems specially the main stem.

The plant has to re-grow that tip in order to send out hormones for flowering to begin.

That usually takes a week or 2.

As mentioned you're getting into the flowering window.

BTW - your plants look great. What's your soil mix?

 

[Simon Limon]

As mentioned you're getting into the flowering window.

BTW - your plants look great. What's your soil mix?

The soil is 50/50 Fox .... [Correction: KoKo Bop soil] and a good local dairy compost, which has been processed to kill weed seeds. I also mix a couple of gallons of perlite into each pot.

I'm using this same mix for cucumbers and tomatoes, all of which are as happy as the clones.

In preparing for my first grow I was able to talk with three different professional cannabis growers and they all said, "Keep it simple!" In addition to the basic soil mix I've been giving some nutes (the details are in my journal) but I'm trying to avoid geeking out over details of pH, etc. Our spring water is slightly acidic so I don't monitor pH.

The greenhouse is kept wide open 24/7 so it is functioning as a grow tunnel until we get into cooler fall weather.

Once they begin to flower do I stop LST?

 

[bobrown14]

You can LST all the way to harvest. I'm doing that now.

The plants know when they are close to the ceiling and will stop vertical growth when they get there.

My plants never grow into the ceiling but they will grow into the lights.

They stop at the ceiling. You could let a few branches go and see if they stop or not.

If not you can just crack them over. The crack will heal over night as long as you have broken the branch completely.

Like this and I broke this one over in flower. She never even blinked. You can see the vascular repair on the btm of the stem to the right of the crack.

DSC_0012 (2).JPG

• bobrown14
• May 11, 2019

Jellium - main stem 10" under lamps

DSC_0012 (3).JPG

• bobrown14
• May 11, 2019

Jellium - main stem crack