LBH's Famous Scrog Tutorial
by LBH - ScrOG and LST expert - View original article by LBH on Rollitup
Note: This article continues where LBH left off in his 4-way LST tutorial.
Scrogging, or screen of green, is a form of LST (low stress training) where the main goal is to maximize the footprint of your light(s).
This is done by dividing, or breaking down the main cola, in conjunction with raising all the lower bud up to the canopy.
We grow the plant horizontally until we are a few weeks into the Flowering stage.
Important! Keep Growing Plant Horizontally Under the Screen Until A Few Weeks Into the Flowering Stage
This is a key point as many attempts at Scrogging turn out to be merely a skeletal support structures for standard plants, not real Scrogs.
A Scrog is when you bring those arms up and run them lengthwise under the screen. All those would-be popcorn buds become real buds because they become part of the canopy and receive direct light.
Lower buds are brought up to the screen or the screen is lowered, allowing them to become a part of the canopy.
With standard, Christmas tree style plants, you can only lower the light until it’s close enough to the top cola. ANY bud from there down is getting less light. With a traditional setup, the lower each bud is on the plant, the less light those buds get.
The purpose behind Scrogging is to manually change that by putting all the bud on an even layer by bringing the low stuff up (by getting screen good and low) and bringing the main cola down (by ping it via topping), to the canopy.
The rough pics below illustrate my point.
Now to break down the main cola and get the plant growing horizontally, I suggest trying my 4-way LST method.
I have tried pretty much most of the standard things you can use for screen. Below are the 4 main ones used, listed in my order of preference
1.) STRING - The very best. Laces up quick and easy and you just snip, snip, snip come harvest time. Throw it away and lace up a new one.
2.) Twine/hemp cord - Pretty much the same ease of use as string but you get hairs in the buds from fraying.
3.) Plastic fencing - works well but is kinda sloppy looking.
4.) Chicken wire / fishing line - The 2 worst
Chicken wire is terrible because the buds actually grow into it and you have to “cut” your harvest out. Snipping up chicken wire into a bunch of smaller pieces sucks, you get poked a lot and is an overall nightmare compared to string. Does it work as a screen? Quite well, but chicken wire sucks to remove.
The fishing line is also bad news as it can cut a stem, arm etc, very quickly and easily. Consider it to be “sharp”. I have only used 12 lb test, I imagine something in the 30+ range might work pretty good though. Avoid any “braided” fishing lines especially
This is my version of a screen that is both easy to work and re-usable forever. I simply lined a square of 2x4's with eye hooks
Many build feet for their screens. This somewhat limits you.
I like having screens where the height can be adjusted either by a peg system or some other ingenious way.
I use shower curtain rods for mine and they work well, but you have to get used to not leaning on the screen or disaster can be right around the corner. To me, it’s worth it not to have legs in the way. It allows more room for “under canopy” cleaning and maintenance.
So now that we are all laced up and ready to go, let’s talk about a key element to Scrogging,….Veg time.
How long should you spend in the vegetative stage when growing under a Scrog screen?
Veg time varies greatly mainly with method.
With Hydro, it’s much shorter. I used to veg 6-8 weeks in soil and now in hydro, that’s cut in half.
Here's a general rule to follow: the screen should be no higher than 8” above the medium or plant base. You then fill your screen during the stretch by tucking (that’s coming) all those arms into the empty voids.
Important note: In Scrog, the screen should not be more than 8" above the base of the plant.
The truth is, the length of time spent in the vegetative stage is something you just have to play with to really learn. You need to gain the experience of actually running a screen that could have taken more plant to fill (needed more veg time) and also running one that is too crowded.
Once you get these experiences under your belt, you’ll really have a feel for veg time. You must tailor the veg time according to how many plants you're growing and how big the screen is. Sorry I can’t help more on this category, but this is the one you have to do to learn.
Topping (Illustrations in the 4-way LST tutorial)
By topping, we create more of these arms to spread out across the screen.
That, to me... is the whole point of a Scrog.
If I didn't top, I'd have 1 cola higher than the rest, thusly, limiting my light height.
By topping, that main cola gets pided down the buds are all level on the screen, allowing you to get that light right down on them for nice, even coverage. The expanse of the footprint will limit your height before heat does. (I have a/c lights)
The above plant was topped once. This gave me 2 arms to run under the screen, split like a V at the base where I topped the plant.
I normally build a plant like seen in my 4-way LST tutorial. I grew this one out specifically to illustrate how to run a branch horizontally under the screen. It will have 2 main colas, large, not XL as it was pided once already.
One more topping (4-way) and that pretty much pides the main into 4 med to med/lrg buds. Perfect.
As I said, this one was grown specifically so you could see how to grow an arm horizontally. This plant, if you wanted to name it, got "2-way" LST, which basically means it was only topped once. I run 4 plants under a 4x4 screen and top twice (in hydro) (4 times when I ran soil).
Top any more and you'll get MORE... SMALLER buds.
Tucking is easy but takes care. ALWAYS TUCK SLOWLY AND CAUTIOUSLY
This is what I mean by tucking:
While those arms are stretching, you allow each one to grow up and through a square in the screen. I like to get them about 2”-3” above the screen and then I GENTLY, pull it below the screen and move it to the next square away.
You continue to do this all throughout the stretch, …continuing until about 2-3 weeks into the Flowering Stage.
Remember, you are controlling where that arm is going by moving it 1 square at a time. You can change your mind tomorrow if you see the need for it.
The screen takes constant manipulating until the last stretch is over but once it's done, so are your Scrogging duties.
To obtain maximum control don't be afraid to work add more bondage if needed. Zip ties are awesome and can be easily cut out with the fiskars pruners later.