How does SCROG improve my canopy and yield?

Smokin Moose

Fallen Cannabis Warrior & Ex Moderator
** The ScrOG Concept **

Growing with fluoros gives one a good understanding of light to plant distance because it's so critical. Even so, HID users still appreciate the impact of having as much growth as possible, as close as possible to the light. It's how to make best use of what you have.

In the process of achieving the above, the shape of the growing canopy would match a line in space where light intensity would be equal as it eminates from the light source. With fluoros, it's a perfectly flat plane. With a stationary HID it's a concave shape, the degree of which depends on the area covered. With an HID on a light mover, it's a perfectly flat plane.

Training is a method of growth control that allows one to shape their canopy. Tying, bending, crimping, topping, are all training methods. Training branches to grow where one wants in order to get the desired shape takes time. At best, even though branches are where one wants them, when the canopy is in full flower there are void spaces between the buds where other buds could be growing, but aren't.

The Sea of Green method, where many plants are used in an effort to eliminate the void spaces between buds, was named from the vision of seeing the procsess in use. The canopy looks like a "Sea of Green".

Either way, extra effort is required to maximize the use of canopy space. The plant's shape and the shape we want from a canopy under artificial lights are simply not the same. IOW Mother Nature will not cooperate:) The extra effort comes in the form of using more plants (SOG), or training fewer plants.

After finding from experience that I didn't like maintaining the numbers of plants, mothers, and clones needed for SOG I opted for using fewer plants. I had to train but still wanted that Sea of Green horizontal profile and no void spaces in my canopy.

Enter the Screen
When a length of poultry netting is stretched over the grow area, it eliminates the need for conventional training. Tying, bending, and crimping are replaced by using the netting as anchors to keep shoots in position. It can also be perfectly shaped to make best use of the light. The netting is known as the screen, hence the name Screen Of Green or ScrOG for short.

Plants are topped to promote branching, as the plants grow into the screen and their shoot tips start to grow through the holes in the screen, they are pulled back under the screen and guided to the next hole to continue their horizontal growth. All the time maintaining the profile of the screen to maximize light use. Growth is very robust. While now getting the same light intensity as the primary shoot tips, secondary growth seems to blossom, and from the secondary growth comes tertiary growth, etc.. All at the top of the canopy, and all receiving maximum light intensity. How many plants are used depends on how much time the grower wants to take to fill the screen to a point where it will be full with buds at harvest. This will largely depend on the growth traits of the variety he uses, but one can fill a canopy with only one plant if desired.

When flowered, only the slow growing buds are allowed to grow through the holes in the ScrOG. The resulting harvest profile is indeed a Sea Of Green but with much fewer plants and the increased yields gained from making use of the void spaces found in a conventionaly trained, non-SOG canopy.
 
Hey everyone,

I am thinking about growing a ScrOG but I'm a little confused about something. When the plants reach the screen and you begin training them, do you weave the plants in and out of the chicken wire or do you pull it back out of the hole so that it's under the screen and then direct it towards the next hole so that the plant stays beneath the screen the entire time? Thanks in advance for your help!
 
The latter. When you install the screen, you set the light as close as the plants will be able to stand... generally not rasing it. Keep all growth (just) under the screen. Only when you are in flowering and the buds are growing (everywhere) do you allow them to grow up through (all of) the holes in the screen. And start raising your lights.

Forcing/training the plant under the screen has multiple benefits; it both forces the plant to branch out (by keeping the growing tips at the level of the rest of the plant and thereby redistributing certain growth hormones within the plant) and provides an even, flat canopy so that your lights can shine at full brightness on all of the growth.
 
Yeah, what Tortured said...basically think of it like LST'ing but on a larger scale and without the need for clips and wire or string to hold the branches down. By keeping the main tip lower than the rest of the growth you are redistributing the growth hormone called auxin (I think, had a few beers lol) to the "lower" parts of the plant causing them to stretch upwards toward the light in an effort to become the new top. As you retrain the new growth to stay below the screen this same hormone is continuously redistributed throughout the plant causing growth to stay roughly even across the screen.

Then, as Tortured said, when you flip over to the flowering stage you allow the new growth sites to begin to stretch upwards towards the light and develop your buds that way. Instead of having one main cola off the main tip you will have a bunch of "main" colas distributed throughout the screen.
 
From what you say, it sounds like you start the screen process while the plants are still in veg... would it work if started after they were flipped into flower (for those of us with separate veg & flower rooms)?

Kind of defeats the purpose; yes, plants will stretch during the first portion of the flowering phase, but not enough to populate a screen that will have every hole filled with a nice bud by the end. And if you increase plant density enough to make up for this then you are sort of defeating the purpose.

IDK what type of grow style you are using. Perhaps you could build a screen onto your plant containers so that they could be growing into it while in your veg room? I know that some have in the past done this, although it can quickly become a pain when one's screen sizes are eight square feet and one has quite a few of them...

Also, do you find it more difficult to water and feed (e.g., mixing guano into the top few inches of soil), and train too I suppose, the plants in the middle & at the back? My garden is set up in a corner so I`m assuming that to do scrog, I will have to rearrange things so I can walk all around it, yes?

As far as watering/feeding... I guess by your query that you aren't growing hydroponically lol. Still, when watering a "pot," you don't really need access to 100% of the "soil's" surface. Having the ability to water (and deal with runoff) with your containers "in place" is important.

And as for training... Plants trained from day one seem to be pretty "flexable," as anyone who has ever goofed and had to redo their screen knows. The individual, of course, must decide how much space he/she needs between the top of the container and the screen in order to facilitate adequate access. The grower who can reach in from all four sides has it easier since he/she only really has to be able to reach in halfway from any point. In your case, it might be useful to leave more space since you would have to be able to reach all the way through.

If done correctly it's easier than you might at first think since there will be little to no vegetation under the screen - other than the network of stems/trunks - due to the canopy blocking useful light and your training to take advantage of it.
 
I have some plants that are 4 weeks into flower (with probably 4-5 weeks to go) and I keep wondering if it is too late to try to increase the light to the lower buds -- are they too far along to try scrog at this point do you think?

Way too far along for scrog. BtW, if a plant is still stretching at the end of the 4th week in flower then you're looking at at least 70 days total flowering (the stretch phase amounts to 40% of the flowering period).
 
After finding from experience that I didn't like maintaining the numbers of plants, mothers, and clones needed for SOG I opted for using fewer plants. I had to train but still wanted that Sea of Green horizontal profile and no void spaces in my canopy.

I Hear that I got 22 2liter hempys and it gets kinda tedious hand watering em all every other day
 
I'll be scrogging this new grow. Currently, I have 7 girls at 35 days from seed. I've fim'd once. I plan on starting to train them under the screen this Wednesday; will flip the lights about 10 days after.

This will be my 4th grow, but only my second uding good genetics & proper lighting. I'm using 2 grow tents (2x4x5 & 2.5x5x7). My last grow stretched more than Ibanticipated, leaving me with half my crop being severely light stressed. Thought I'd see if scrog could help me improve my crops.

I'll start a journal once I get the screen going. I'm going to need all the feedback I can get.
 
What sized mesh is best? Would 3" squares work? 2"?

I cannot say what sized openings are "best," but I have used various things, including "chicken wire" (poultry netting) that had holes a mere 1" in size. I actually rather liked that - because, at harvest time, all I had to do was to saw the trunk off just below where it began branching, then disconnect the screen from the walls, and - with a helper - carry the entire screen/plant combination in to my dining room table. I've found that harvest work is a lot easier sitting in a reasonably comfortable dining room chair than squatting down at/in a small grow space, lol. And the relatively small hole size meant that there was zero chance of things falling out while the screen was being carried to the other room.

Smaller holes also means more of them, which in theory gives one more choices in terms of deciding where to move each growing tip.

How large is too large? Well, the point, IMHO, is maximum production in the space - so I would not wish to use anything that has holes sized appreciably larger than the size (area) of the buds. In other words, if your buds are 2½" in diameter, then a screen with 5" holes would seem to waste real estate. Of course, the leaves take up space, too, but...

One important consideration: If the gardener is growing multiple strains and/or phenotypes, it is highly unlikely that everything will be ready for harvest on the same date. If that is the case... I would not want to have to separate one plant that is ready from one or more that isn't at all, but I probably would not even make the attempt if I had used 1" hole poultry netting (and had 100 or more buds growing up through the holes :rolleyes3 ) . In that scenario, I'd end up just trying to cut the "ready plant's" buds off above the top of the screen and - somehow - cutting loose and removing that plant's branches/roots/container from the grow... And I seriously doubt I'd get everything, which would leave dead plant material in there. Another term for dead plant material (IMHO) is "an excellent place for undesirable things to thrive."

I've fim'd once.

It's been my experience that most strains will branch (in extreme amounts, lol) without having to cut the top off of the plant when properly grown via scrog. And that begins pretty much as soon as that first (primary, at that time) growth tip has grown up through the screen enough that the gardener is able to pull it back underneath the screen. Plants seek light and - since they have no brains ;) - this is facilitated through the distribution and redistribution of auxins/hormones. In this case, when the primary tip is no longer the highest part of the plant (because it has been pulled back down), there is a redistribution of auxins to the other branches that causes them to begin growing at an increased rate.

In nature - where plants evolved in the first place - all of this is important because if the top of the plant encounters an obstruction, it cannot continue to grow towards the Sun. No sunlight, no energy production. Which it must have to complete its mission in life (the production of offspring). Causing the "non-primary" branches to now grow upwards gives the plant a much better chance to get at least some part of itself into the sunlight. Others can undoubtedly state this much better, BtW.

"But if branching is important, why not cut the top off of the plant? Doing so obviously provokes branching." Yes, but if you are reaching towards the ceiling and someone cuts your arms off, it means your reach has been appreciably shortened, lol. Topping a plant delays the point at which it reaches the screen - if for no other reason, because it has to grow an additional {however many inches you removed} just to get back to the height that it was before you topped it. To say nothing of any potential delay (which may or may not actually occur in practice) due to stress.

I plan on starting to train them under the screen this Wednesday; will flip the lights about 10 days after.

I always placed the screen at whatever height (varies) that I happened to feel gave me room to get my hands/arms under it when things were really crowded under there. I gave more room if, for example, I was not able to access the plant from every side (if I only had access from the front, it meant that I had to be able to reach all the way to the back instead of just halfway). I generally installed the screen as soon after placing the plant(s) into the grow space as possible. And, for me, training began as soon as the top of the plant reached the screen (+ just enough additional height to be able to be pulled down and sent horizontally instead of vertically).

Therefore - and, again, for me - it was a lot more than ten days between the start of training and the switch to a flowering light schedule.

As in most things, there are many ways to do the thing and it would be difficult to determine ONE best way, your mileage may vary, et cetera.
 
Yaman, all over this. Just not looking forward to getting one plant out when it is ready waaaaaaaaaaaaaay b 4 d others. Mabe just cut the best nugs off and reveg for a monstercrop job. Time will tell. Opinions? Experiences?
 
I cannot say what sized openings are "best," but I have used various things, including "chicken wire" (poultry netting) that had holes a mere 1" in size. I actually rather liked that - because, at harvest time, all I had to do was to saw the trunk off just below where it began branching, then disconnect the screen from the walls, and - with a helper - carry the entire screen/plant combination in to my dining room table. I've found that harvest work is a lot easier sitting in a reasonably comfortable dining room chair than squatting down at/in a small grow space, lol. And the relatively small hole size meant that there was zero chance of things falling out while the screen was being carried to the other room.

Smaller holes also means more of them, which in theory gives one more choices in terms of deciding where to move each growing tip.

How large is too large? Well, the point, IMHO, is maximum production in the space - so I would not wish to use anything that has holes sized appreciably larger than the size (area) of the buds. In other words, if your buds are 2½" in diameter, then a screen with 5" holes would seem to waste real estate. Of course, the leaves take up space, too, but...

One important consideration: If the gardener is growing multiple strains and/or phenotypes, it is highly unlikely that everything will be ready for harvest on the same date. If that is the case... I would not want to have to separate one plant that is ready from one or more that isn't at all, but I probably would not even make the attempt if I had used 1" hole poultry netting (and had 100 or more buds growing up through the holes :rolleyes3 ) . In that scenario, I'd end up just trying to cut the "ready plant's" buds off above the top of the screen and - somehow - cutting loose and removing that plant's branches/roots/container from the grow... And I seriously doubt I'd get everything, which would leave dead plant material in there. Another term for dead plant material (IMHO) is "an excellent place for undesirable things to thrive."



It's been my experience that most strains will branch (in extreme amounts, lol) without having to cut the top off of the plant when properly grown via scrog. And that begins pretty much as soon as that first (primary, at that time) growth tip has grown up through the screen enough that the gardener is able to pull it back underneath the screen. Plants seek light and - since they have no brains ;) - this is facilitated through the distribution and redistribution of auxins/hormones. In this case, when the primary tip is no longer the highest part of the plant (because it has been pulled back down), there is a redistribution of auxins to the other branches that causes them to begin growing at an increased rate.

In nature - where plants evolved in the first place - all of this is important because if the top of the plant encounters an obstruction, it cannot continue to grow towards the Sun. No sunlight, no energy production. Which it must have to complete its mission in life (the production of offspring). Causing the "non-primary" branches to now grow upwards gives the plant a much better chance to get at least some part of itself into the sunlight. Others can undoubtedly state this much better, BtW.

"But if branching is important, why not cut the top off of the plant? Doing so obviously provokes branching." Yes, but if you are reaching towards the ceiling and someone cuts your arms off, it means your reach has been appreciably shortened, lol. Topping a plant delays the point at which it reaches the screen - if for no other reason, because it has to grow an additional {however many inches you removed} just to get back to the height that it was before you topped it. To say nothing of any potential delay (which may or may not actually occur in practice) due to stress.



I always placed the screen at whatever height (varies) that I happened to feel gave me room to get my hands/arms under it when things were really crowded under there. I gave more room if, for example, I was not able to access the plant from every side (if I only had access from the front, it meant that I had to be able to reach all the way to the back instead of just halfway). I generally installed the screen as soon after placing the plant(s) into the grow space as possible. And, for me, training began as soon as the top of the plant reached the screen (+ just enough additional height to be able to be pulled down and sent horizontally instead of vertically).

Therefore - and, again, for me - it was a lot more than ten days between the start of training and the switch to a flowering light schedule.

As in most things, there are many ways to do the thing and it would be difficult to determine ONE best way, your mileage may vary, et cetera.

Thanks for this TS! I've tried scrogging twice now and I'm just not getting it, I thought you were supposed to FIM and top to get more branches, and that's why mine never really fill out the screen because I never get much branching. But instead you're saying it's more a matter of training them earlier?
 
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