SCROG Tutorial

All you need to know about the Screen of Green

Welcome to our ScrOG Tutorial! In this article we are going to go in depth on what SCROG is all about, from what you need to do one, to the advantages, passing by a detailed how to guide and much more.

Here are each sections of this tutorial if you want to jump straight to the part that interests you:

<h2id=”what-is-scrog”>What is SCROG or the Screen Of Green ?

SCROG is the acronym if Screen of Green. This technique of cultivating your Marijuana allowing you to have multiple Apex’s on your plant.
Basically the idea is to have your plant follow a screen, giving the branches that grow direct access to the light source.
With more access to light your branches will be able to produce more energy, giving you some nice big buds!

Look at the image on the right, you can see new branches starting to sprout up on the screen.
Those little branches will be full grown flowers soon enough.

Personally SCROG is one of my favorites, it takes longer to produce but once you get the hang of it you save a lot of time.

Before getting the “How to” section of the page, lets go over the pro’s and con’s of scrogging.

2 Blue thai plants starting to cover the screen

What are the pro’s and con’s of SCROG?

The pro’s:
  • High yields of buds per plant
  • Less plants to take care of
  • Reduced time to water the plants
  • You get some MASSIVE plants
The con’s: 
  • Longer vegetative stage
  • More nutrients per plants are needed
  • Guiding and clipping branches is time consuming
  • Danger of breaking the branch when weaving the plants if you’re not careful

When to SCROG?

Choosing when to ScrOG can depend on different factors, here’s we’ll cover the major ones.

  • You don’t have many plants within your grow room but still want maximum yield.
  • Reducing the time needed to take care of your plants is an objective of yours.
  • You want to maximize the yield produced by each plant.
  • Looking to make some massive plants.
  • You’ve heard about it and want to try it out.

Looking around these have been the main reasons why growers choose to go for a Scrog.

When to get the branches onto Screen?
top branches and leaves passing over the screen

Big Buddha Cheese ready to start being weaved onto the screen

What do I need to set it up?

In terms of equipment you don’t really need much, all you need is:

  • A screen: Try and have square spacings of about 10cm wide. You can either make it yourself of buy one at a gardening store
  • Large buckets or pots: In order to scrog your plant will need to have a strong root ecosystem during its flowering phase, so don’t hesitate to get her at least in a 10L bucket
  • Scissors or a razor: You’re going to need to trim leafs and branches pretty often, to do so a pair of scissors or a razor is best.
  • Clips and/or string: In order to guide your plant you’re going to need to guide the branches on the netting.
    To do so I find string to be just perfect, not too aggressive for the plant, flexible and allows you to pull it in the direction you want.

How to prepare Marijuana for a SCROG?

In order to have a nice scroggable plant your going to have to train it very early on. The objective of this training is to make the plant stop focusing on her main Apex a bring nutrients in an equal manner to each section. The second target is to start developing the branches early on so that by the time flowering stage comes you’ll have some nice sturdy branches able to handle their weight.
That’s cool on paper, but how to you do this in the real world… here’s a couple easy steps to get this done!

Training Weed for a Scrog Easily

We’re going to show you how to do so with a newly germinated plant and with our Big Buddha Cheese cutting 🙂 so that you can see that it’s simple and generally doable.
We’ll start off with 2 pictures before we started training them, then get into the steps. By the way, if you want to follow the life of these little one’s, check out our weekly grow reports 😉

Plant 1 – Young Blue Kush Weed Plant

Blue Kush about 15 days old before starting the scrog training

You want to wait until the 3rd stage of leaves before doing anything. In the picture above we must wait a little before starting to train this one.

Plant 2 – Big Buddha Cheese Cuttings

2 BBC cuttings showing strong deficiencies

You can’t really tell on this picture, but the cutting on the right has a nice potential of starting of as a perfect V. Pretty exciting for since we had planned to SCROG anyway.

Step 1 – Pruning the Apex

Once your plant has grown her 3rd stage you’re going to want to cut (prune) the top section of the plant with a pair of clean scissors or a blade.
As we show in the picture below, you’ll want to do this just above the knot, be careful not to damage the side branches that are forming!

In the next step you will be able to see what it the plant will look like without the Apex. If you’re worried about the fact that the Apex is supposed to be her strongest and best bud, don’t worry, you’ll get that bud x10 😉

Step 1 – Transplanting and Pruning the cuttings

As you saw in the image above, these cuttings were alive but showing strong deficiencies. We also said that one little one showed a nice V shape potential. As you can see in the image below, with a nice leaf pruning and a transplantation it’s definitely there now.

V shaped BBC strain ready to start scrog training

All we really did here is remove most damaged leaves, leaving here a couple for her photosynthesis, and pot her deep enough and at an angle where the branches would both be facing upwards.

Step 2 – Let the 2 new Branches Grow

2 strong branches growing where apex was cut

After cutting the Apex you’re going to want to wait until each side branch has developed a new stage of leaves.

Step 2 – Leaf and branch growth

BBC cutting recovering after transplant

As you can see within a small week this little one recovered beautifully. If you also have a cutting they’re can sprout many site branches, don’t hesitate to cut of the sites that won’t be developed (too low, too close to another one, etc)

Step 3 – Prune Tip of the 2 new branches

Now as you can see we waited a little too long to cut the tip of the side branches. Generally you’d want to cut it before the growth of the next stage in order to avoid any waste of energy. With that in mind, we’re still going to keep the 1st stage branches, in time we’ll prune the 2nd stage growths and that top leaf that’s shading the branch.

Step 3 – Increase light penetration

Training plant by tying the stem to the pot

This little one was starting to grow some big leaves creating a lot of shade. Instead of pruning we decided to take advantage of that nice V and pull the plant apart. The main thing to be careful here is not to make a tight knot around the stem of the plant. The last thing you want to do is obstruct the flow of nutrients or break the outer skin.

Step 4 – Let the new sets of branches grow

new set of branches growing near the cut

You should see pretty quickly 2 new branches growing on the knot near the cut and each side.
At this point you’re going to want to let each sprout grow a little before starting to train her. You’ll have 2 options.
The first, prune them again, making a total of 8 branches. The other, letting the grow and placing the screen once they’re tall enough (we cover that further below).

Step 4 – Growth of new branches and Leaves

By now we’ve got 4 strong branches and many smaller one’s starting to grow. We could start placing the screen and start weaving her on it, but the other plants are far from ready. Taking that into account, we decided to keep training her with string in order to increase the amount of side branches and overall size of the plant, which will be our next step.

Step 5 – Training the branches

rope tied to branches in order to increase light penetration

In order to improve the growth of the side branches you need to give them direct access to light. As soon as they are big enough to start creating shade to one another you’re going to need to give them room.
You can do this by attaching and pulling each branch away from the other.

Step 5 – Branch training to improve light penetration

strong plant training, spreading her to the 4 corners of the pot

By looking at her like this you might this this isn’t good, maybe even cruel for this little marijuana plant. But by attaching her to the 4 corners like this we’re actually increasing her ability to get a direct source of light, thus stronger photosynthesis capabilities. In just a few hours she had already started standing up, by the next day she was thriving.

Once you’ve reached this stage you can keep on training your plant, multiplying the number of branches, or start placing your screen and get the branches through for the weaving process, it’s really up to you.
If you decided to keep pruning and training you just need top repeat steps 3 through 5.

Here’s what the stalk of this plant looked like at the middle and end of the vegetative stage

Evolution of the pruned plant during the vegetative stage. Now 4 strong colas

About half way through the vegetative stage

End of vegetative stage, the pruned areas gave 4 strong branches

End of the Vegetative stage – Strong stalk and 4 cola bases

End of the vegetative stage – Top part of the trained plant

How to do a Screen Of Green

There are multiple steps to setting up your scrog and as you’ve seen in the steps above the plant training can start early on in the vegetative stage, so make your decision early on!
Let’s cover the steps on how to set up the scrog Method

How to SCROG in 5 easy steps

  1. Attach your screen
  2. Prune your leaves and branches
  3. Guiding your branches horizontally on the screen
  4. When to start flowering
  5. SCROG and the flowering stage

Let’s go through these steps with more detail:

1. Setting up the screen for a SCROG

So what you want to do here is get your screen at about 40/50cm (15/20 inches) of the top of you’re pot, and attach it by the four corners of your grow room. I use metallic string for this (cf image), attached on the 4 corners of the room.
As a safety I also add 3 strings, attached from the top of each side of the room onto the sides of the screen, just in case something happens. Once those branches start invading the screen you don’t want it to get moving.

Once you’ve done so, here’s what to do:

Screen place in the grow room

top view of Screen set up for scrog

Screen fixed over the plants

room left between apex's and screen

At first leave some room on top of the Apex’s

Gently Slide the Screen Down

Once your screen is fixed you’re going to want to slide it down so that the plants start to go over the Apex’s. Do this gently, you don’t want to break anything!
The main advantage of doing this is to save some time, scrogging already strongly extends the vegetative stage, might as well save some where we can right?

screen lowered, Apex's and top leaves over the screen

Highest Apex’s pressed by the screen

Plants passed through the screen

Slide the screen down until it reaches the top of the plants and start passing the stems and leaves through each whole.
After this step all the leaves and branches that are touching or nearly touching the screen should be guided towards a whole.

Lower the screen again

top branches and leaves passing over the screen

Apex’s guided through the whole

Very little room between top of pots and screen

At this point you’ll want to do the same thing as the previous step. You should have more branches and leaves that and tall enough to pass or weave through the screen.
On our end we would of liked to lower in tad bit more during this grow but if we did we wouldn’t have enough room to water and all.. So we stopped here, but you can repeat this as much as needed!

2. Pruning your leaves and branches

Once your branches start to reach the screen, it is important for you to cut some of those leaves and branches, here’s an easy way to choose:

  • Cut the Leaves: That aren’t receiving light under the screen
  • Cut the Branches: That will either take too long to reach the screen or that will cross paths with another branch with more potential.

Here’s the before and after one of our prunings:

about 15 colas removed from the 2 big Buddha cheese plants

After first pruning

10/15 branches and leaves pruned off the plant

Some of the pruned leaves and branches

I know it will hurt and you will be hesitant, but really don’t be, cut everything that isn’t going to produce energy, that take’s the space of another or produces shade over an area.

Your plant will thank you by growing much faster on the top of the screen, where everything has direct contact with the source of light.

3. Guiding your branches horizontally on the screen

Now it’s time to get your plant to fill up the screen. You’re going to want to take your main branches and chose which direction they’re going to go in.
Follow these steps:

  1. Identify the direction you want each branch to go in. This planning step is important, you want to make sure that each branch has at least one free space to its left, and one to its right
  2. Bend the top of the branch over the first line and under the next one.
    Don’t hesitate to tie down the branch onto the netting so that it holds.
    In the first image on the side here you can see how we tied the apex on both nettings in order to pass her under and over the screen.
  3. Cut any leafs making shade to a spot where a branch could come out. You should also cut the branches that are to close to each other. At each not you should have tops 1 branch growing vertically.
  4. Take a string, on one end tie it around the top of your branch and the other tie it in the direction where you want you plant to go on the screen. Don’t hesitate to pull well on her she can take it.
    You can see on the last image of the set how each branch is weaving over and under the screen, as well as the green string pulling them in the direction we want her to go.

Thanks to this technique, with just one plant you can actually fill up a whole grow room! the only thing is that you’ll keep her in a longer vegetative stage.

guiding the apex over the screen during scrog
the top of each branch has been folded over and under the net
plant weaved over the net and string pulling the branches

 

4. When to start the flowering stage

At the latest, you want to start the flowering stage once your screen is filled up or almost so. You don’t have to wait until it’s full, just don’t wait too long since remember the first 2 weeks is the stretch, and as we’ve seen in our FAQ covering the differences between sativa and indica weeds, the amount of growth during the stretch depends on the strain. With some, the growth can be massive!

With Sativa’s you can keep on weaving during the first days, some even week, of the stretch, indica’s it’s best to have finished before launching.
Here’s a couple pictures ouf our own during the stretch, and a link to the blog post about the start of the SCROG

Starting the flowering stage

End of the vegetative stage

Scrog mid way through the stretch, screen is full

Mid way through the Stretch

Ending the Stretch – First pistils are showing

5. SCROG during the flowering stage

The Early Flowering Stage – Buds forming

Once you’ve entered the stretch and stopped weaving the plant the process is pretty much the same as with any marijuana plant.
Here’s a couple pictures of our babies once they had started forming their buds, you can see that the they’re still more or less still at the buddlet form at this point.
As always, click on the image for a full view.

Top view of 2 plants scrogging during the flowering stage

Horizontal view on 1 plants multiple branches

Trichomes starting to appear

While the buds keep on fattening up you’ll start noticing a sticky power-like dust on and around your buds called Trichomes. These little guys are produced by the plant for many different reasons, such as defense (unwanted invaders get stuck). In our case they’re interesting because that’s where the THC and CBD will be stored.

Now keep in mind that at this point in time there is no THC what so ever within the plant, if you harvest now you’ll be wasting all your efforts for nothing.

What are Trichomes? Check out our in-depth Article

Trichomes starting to appear on flowers and leaves near the flowers

Bud and Trichome development

During the next couple weeks the plant will keep on growing its flowers. You’ll see the pistils go through one, two maybe even 3 rounds of browning pistils. Just sit tight and wait until those trichomes are just right for you, personally we uppers so we go for milky Trichomes, when the THC is at its highest.
If you want some chiller bud, wait until they start to become a brown/golden color, the THC levels will be lower and the CBD will be higher, giving out some chiller effects. Here’s a couple pics of this stage

Buds have nicely fattened, but not quite there yet

fully formed trichomes on marijuana leaf

Trichomes are formed but still mostly clear

Marijuana pistils browning

Pistils starting a browning phase
(remember, not a sign of readiness)

Choosing the moment when to harvest is really linked to the status of the Trichomes. As we said above, milky trichomes are a sign that the THC levels are at their highest, whereas if you wait a little they will start deteriorating, turning a golden/brownish color. This is a sign that the levels of THC are reducing and the CBD is rising.

ScrOG vs SOG

This is a big one, we’ve received many messages from you guys wondering what was better, scrog or a sea of green.
Since they both have their advantages and disadvantages we decided to group them all together so that you can make you own decision.

Screen of Green vs Sea of Green

Comparison Scrog SOG
Advantages
  • You maximize the use of your space with a small number of plants
  • Less plants to take care of
  • Higher render per plant than any other technique
  • Shorter vegetative
  • Increases the number of plants in the grow room.
  • Your buds will be nice and dense
Disadvantages
  • Longer vegetative stage
  • Once the screen is set you will not be able to move your plants
  • Not compatible with auto-flowering seeds
  • More plants to take care of (watering, deficiencies, etc)
  • Best to use clones
  • Each plan will render less flowers at harvest time, although they will have one, fat, bud
  • Your plants don’t have much room to breath and grow

Do I need special Grow Lights?

No, you can go for a scrog with the light system that you usually use within the grow room, although you do need to make that the light covers a wide area in order for the cannabis plant to be covered while growing horizontally.

So think more in light coverage, you can keep the same intensity and spectrum of light.

Can I SCROG with any seed?

Technically yes, although it is though with auto-flowering seeds since you can’t control the length of the vegetative stage.
My advice would be to take pre feminized seeds of the strain of your choosing.

Can I SCROG with any strain?

Yes! it is totally possible to scrog with indica or sativa weeds. Although you will adapt a little, the indica strain growing less during the stretch, your vegetative stage will have to be longer.
On the other hand, with sativa weeds you can switch to 12/12 earlier and keep weaving a little while during the stretch phase.

You should also take into account the genetics of the plant and check if it’s known to develop strong side branches and bud sites.

Don’t feel like reading? I Love Growing Marijuana put together a pretty neat video explaining the different steps to scrogging, check it out:

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