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How to ScrOG Cannabis — A Complete Guide

Added 26 January 2022

The Screen of Green method, also known as ScrOG, is used by cannabis growers worldwide to maximize their yield with less space. The method has become quite popular in recent years as more and more individuals are growing cannabis at home. 

The ScrOG method can benefit you if you want to get better yields, but it can be a little tricky to understand the basics. Moreover, the technique will work only if you combine it with other training methods for the best results. 

This article will help you learn everything you need to know about getting extensive yields using ScrOG. Plus, there’s a step-by-step tutorial we made just for you. 

ScrOG: How It Works

The ScrOG technique gives you more potential to increase yields with grid netting. And, you can use it wherever you want — with or without a grow tent. 

Each grid holds a dominant bud or a cola, as you call it, and the net is held in place using a square structure made of either wood or PVC.

The objective of ScrOG is to make a uniform canopy that allows all the flowers to grow at a consistent rate by getting similar levels of light. If used correctly, this method ensures all the buds are heavy and dense, instead of only the top-tier ones being heavy and thick, with popcorn buds at the bottom.

Benefits of ScrOG

Thousands of cannabis growers use ScrOG for various reasons. Let’s take a look at these benefits.

  • Greater Yield

Typically, ScrOG ensures a much higher yield than plants grown in their natural structure. 

For instance, the cannabis plant grows in the shape of a Christmas tree with one main cola at the top. So, naturally, the buds at the top get all the light, while those at the bottom struggle.

As a result, the dominant bud sites or the tops grow bigger buds than the rest on the lower tiers. 

With ScrOG, you can bring all the buds to a uniform level so each can get better light and air to grow bigger. In addition, the bottom-tier buds will also get their fair share of light and grow to their maximum potential. 

  • Culture Uniformity

If you are growing multiple plants from seeds, your culture may grow inconsistently. You may be growing several strains with different structures. That said, plants of the same strain may also grow differently. 

Basically, you will end up with a grow room full of plants of different sizes, and some plants may grow taller than others, shading the smaller ones from light. In other words, the taller ones will totally overpower the smaller ones and impact their overall growth.

You can ScrOG your plants to avoid this problem, so all tops are uniform and get equal light. 

  • Lower Plant Count

If you cannot grow more than a specific number of plants for legal reasons, you can use ScrOG to improve your yield without growing more plants. Generally, ScrOG can grow multiple bud sites consistently and increase your yield even if you have just a few plants. 

  • Makes up for the lack of vertical space

Have you ever felt your plants may grow much bigger than you thought? What if they exceed your expectations in the vegetative stage? Or, what if you don’t have headspace but still want to grow big plants?

Well, we’ve all been through it. And, in such situations, ScrOG is your savior. However, the faster you start, the better your results. Plus, you could combine it with LST to ensure the plants don’t exceed a certain height. 

  • No light wastage

Whether you’re growing plants with a 300W or 600W light, ScrOG ensures that no light gets wasted. Due to its even canopy, all the tops of the plants get uniform light, and the buds get fatter and thicker, just like you expect them to be. 

Disadvantages of ScrOG

Although there are many advantages to using the ScrOG technique, there are a few disadvantages you should be aware of.

1. Can be challenging to spray

You already know that the plants grow in a uniform canopy using the ScrOG technique. An even canopy may be great to get big fat buds, but it could prevent you from tending to the plants, 

For example, it can be challenging to spray anything on the plants — foliar spray, pesticides, herbicides, etc. — because of the canopy’s thick structure. Moreover, the plants sitting at the far end of the canopy will be neglected. Sure, you can try your best by separating the plants, but it will be tricky nonetheless.

2. Tough to get rid of pests

Adding to the point mentioned above, you will have difficulty getting rid of pests if they attack your plants. Not only will it be tough to spot pests due to the thick canopy, but it will also be difficult to spray pesticides on the plants to get rid of them.

3. Not for beginners

The ScrOG technique will work if you have enough experience to prune or trim your plants at the right time. You must have solid experience and knowledge to understand the plant’s needs and train them when required. That said, beginners can also try ScrOG, but it may take a few attempts to master this method.

4. Difficult to move around

Whether you want to trim, prune, or even water the plants, you must have some space in between the plants to make your life easier. However, ScrOG makes it difficult to clean or maintain the plants due to its thicky bushy canopy. To prevent this problem, you can “Lollipop” the plants (more on this below), so you can focus only on the buds.

5. Tricky to control diseases

Although a thick canopy saves light and presents many advantages, it has one disadvantage — humidity. Due to so many plants huddling next to each other, the humidity increases, inviting several diseases. 

It's also true that if a single plant gets affected by a disease, the entire crop will suffer. For example, a plant affected by a fungal infection will quickly spread it to other plants. Unless you remove the affected plant, you risk the entire crop, so it's essential to pay attention to the plants at all times.

Ideal Cannabis Strains for ScrOG

Not all cannabis strains can handle ScrOG. Therefore, we recommend using strong strains to handle the method.

In addition, you can ScrOG both autoflowers and photoperiod cultivars. With photoperiod plants, you can install the screen after training them before switching to the flowering phase with photoperiod plants. 

However, with autoflowers, there’s no set timing for the flowering, and the buds can appear as soon as they reach a specific size. Therefore, it can be challenging to identify the right time to set the screen. In any case, you can set the screen as soon as you see a few pistils appear on your autoflowering plants. 

Look for the following qualities in a strain to know if it will suit ScrOG:

  • The strain must be a vigorous grower
  • It must have dense branching and buds
  • It must respond well to topping, low-stress training, or super cropping

Some of the best examples of highly vigorous strains for ScrOG are:

  • Gelato (Hybrid)
  • Bruce Banner (Hybrid)
  • Super Silver Haze (Sativa)
  • Amnesia Haze (Sativa)
  • Blueberry (Indica)
  • Blackberry (Indica)
  • Purple Punch(Indica)
  • Any genetics of OG Kush

Equipment Required to Set Up ScrOG

To construct a ScrOG grid, you need a few essential pieces of equipment. But before that, let’s look at the dimensions of an ideal ScrOG grid.

Most growers use a square meter (10.7 sq. ft.) of the grid for their cannabis plants, accommodating up to four plants. However, you can construct a smaller or larger grid depending on your strain’s size and growth.

Here is the equipment required for ScrOG.

  • Biodegradable String

We recommend using biodegradable strings made from cotton, jute, or hemp as they don’t contain any plastics that can harm your yield. Never use twine strings, either, because they tend to fray a lot and leave hair in your buds.

  • PVC or 2x4 Lumber

Next, you need either PVC or 2x4 lumber.

PVC is a terrific choice as it is light and easier to lift using a rope ratchet as your plant grows. However, some tend to leach toxic fumes in high-heat conditions, so look for their heat rating before purchasing.

Lumber is also good — it is sturdy, long-lasting, and easy to work with. The only downside is that it is pretty heavy.

  • Fish-eye Hooks

Fish-eye hooks will be drilled into the PVC or lumber structure every few inches, acting as anchor points for the string. So, you need to get many of them. 

  • Rope Ratchets or Stand

Lastly, you need rope ratchets that allow you to lift your ScrOG system as your plant grows. With these ratchets, you won’t be needing a base to hold the system up, either. However, the structure may shake whenever you train the plants. 

To avoid this problem, try to make a simple stand with four legs so the structure can rest on top of it. You can use PVC, wood, plastic, or metal to make the frame. 

Step-by-step Tutorial To Build a ScrOG System to Grow Cannabis

Growing your cannabis using ScrOG is quite straightforward if you follow the right steps and avoid mistakes. It’s not so difficult to set up a DIY ScrOG system, no matter how intimidating it looks. First, let’s look at how you can grow cannabis using ScrOG.

Step 1: Measuring the Materials

Measure

First, start by measuring rope ratchets, PVC or lumber, and strings. But, of course, you don’t need rope ratchets if you want to make a stand.

Ideally, you can place the fish-eye hooks every 2.5 inches. So, to know how many hooks you’ll be using, divide the overall length of the PVC/lumber square by 2.5. 

Step 2: Creating the Outer Frame

Create the frame

Here, you need to cut the lumber or PVC into appropriate pieces and join them using elbow joints to create the outer frame. This frame will hold the entire structure, including the hooks and strings, along with the branches and must be quite sturdy. 

Step 3: Drilling the Fish-eye Hooks

Drill hooks

Now, you have to drill the fish-eye hooks on the inner surface of the PVC or lumber at around 2.5 inches apart. Ensure the hooks on opposite ends are aligned to create a proper grid.

Then, take the string and connect the hooks to their corresponding parallel hooks. Do this until you have a perfect grid of strings running between the PVC/lumber structure.

Step 4: Building a Support System

Place the construction

If you don’t want to hang the frame, you can build a slightly taller supporting frame (at least 4”), so you don’t have to lift the screen at all. But, of course, this also means that you’ll need to train the plants according to the supporting frame’s height. 

Alternatively, use the rope ratchet system to anchor the corners of the PVC/lumber square and lift it up. As mentioned already, we can even use legs under the frame for support, but they won’t offer the same flexibility levels as a rope ratchet system. 

Why is flexibility needed? As your cannabis plant grows under the ScrOG, you will have to raise the entire grid to align it with your plant’s height. Doing so with support legs is quite tricky.

However, if you don’t do it right, the rope ratchet could keep shaking, which is pretty annoying. In addition, no matter what you use to hang the frame, make sure you never lean down on it or apply any sort of pressure because the screen may crash on the plants and even kill some of them. 

Step 5: Choosing the Right Cannabis Strain

You can choose clones or seeds for this step, but ensure the strain will grow vigorously. 

Allow the plants to grow at least five nodes before planting them under ScrOG because their health in the early stages is crucial for the plant to handle the ScrOG method properly.

Step 6: Train the plants

Train the plants

The vegetative phase of your cannabis can last anywhere between 2 to 12 weeks, depending on how big you want the plants to grow, but you have to be on guard always. You’ll have to pull and bend the branches into corresponding grids during the vegetative phase.

But, as mentioned earlier, this rule doesn’t apply to autoflowers because there’s no telling when the flowering phase can start. So, if you’re growing autoflowers, you can proceed to train the plants as usual with the techniques mentioned below and set up the screen when you see a few bud sites. 

If you do this correctly, you will end up with each grid containing a branch that will further grow in the upcoming phase.

Once your plant has grown over five nodes, you have to manipulate its shape to prepare it for the ScrOG grid. Here, you can use low-stress training, topping, or super cropping. Here’s more on each technique:

  • Topping

Topping is an act of cutting off the dominant or apical node of the plant with fine bud-trimming scissors. Once you cut off the apical node, the plant will direct most of its energy to other topmost bud sites. You can also cut or pinch off the tips of the plant using scissors, trimmers, or your fingers. 

Topping sets the stage to train the plant further as it divides the main cola. The more you top, the more bud sites the plant will develop; however, try not to top more as you’re reducing the thickness of the bud every time you top. 

Be sure the plant develops at least four sets of leaves to start topping. You can begin cutting the tips as soon as you see new growth. After topping, the plant’s lateral branches will start growing with vigor and compete with each other for dominance. Dominance is a good thing because they will grow stronger. 

The first time you top, the plant will divide into two primary colas. Next, wait until you see new growth on both colas and top both sites again to give you four colas. So, once the plant has four main colas, you can stop right there. Sure, you can top all four colas again to get eight colas, but it’s not recommended as the buds will be tiny. 

  • Low-Stress Training (LST)

LST and Topping complement each other as the two best techniques to create more colas. LST or Low-Stress Training is nothing but the act of bending the branches, so the lower parts of the plant also get as much light as possible. You can also defoliate or pluck leaves that prevent light from getting to the bottom during the vegetative stage. 

But, how do you bend the branches and keep them in place? Well, you can use thick wires, strings, cloth hangers, or anything else to keep the branches in place but ensure there’s nothing sharp, or it may cut into the plant. These days, you get many tools explicitly meant for LSTing your plants. 

You can also check out our in-depth guide to learn more about this topic. 

  • Super-cropping

Super-cropping is a technique you can use if you don’t want to cut the top. Here, you have to simply pinch one of the branches gently with your index finger and thumb. 

Once that’s done, the plant will respond to preserve itself by starting the healing process and producing additional callus, which will make the branches grow taller for apical dominance.

Do some research and figure out which one you prefer. Next, follow the instructions, and you will end up with an optimal number of branches for the ScrOG system. Remember, the goal is to grow a uniform cannabis canopy.

Step 7: Tuck in the leaves

Tuck in your leaves

At this point, you will see the plants growing vigorously. Once the branches go through the screen a bit, you can start tucking in the leaves below the net so that every grid has one branch allocated to it. Do not try to place two branches in the same net. This is also why you shouldn’t top too much. Typically, four colas per plant are just right for ScrOG.  

Your hard work with ScrOG will pay off once you switch to the 12/12 light cycle, but you need to prepare your plant further before you do that. 

Here, you must regularly monitor your plant for the following things:

  • First, allow adequate space between the branches.
  • The canopy should be consistent.
  • The ScrOG system’s height should be manageable and in line with the plant’s height.
  • The plant shouldn’t be under stress due to over-training or noticeable deficiencies.

If you notice any problems with the plant as per the above recommendations, re-evaluate your plant before switching to the flowering phase. And if you notice any signs of nutrient deficiency, let the nutrient levels stabilize before proceeding.

Also, if you have followed the process correctly, you will notice that the low-tier branches are in line with the apical node. Lastly, ensure the ceiling is high as the plant may experience explosive growth in the upcoming flowering phase. If not, train the plants adequately in the vegetative stage, so the buds don’t grow too tall.

Step 8: Switch to the 12/12 Light Cycle

Flowering

When you switch to the 12/12 light cycle from the 18/6 cycle, the plant assumes it’s winter. As a result, the plant will automatically enter the pre-flowering stage in a couple of weeks. 

That’s it. You’ll see a rich canopy of green leaves and buds — a Screen of Green — if you follow the right procedures. Next, wait for 6 to 8 weeks for the flowering process to complete, then start cutting the flowers in the corners and work your way inward.

Step 9: Lollipop the Plants

Lollipopping

We already mentioned that it’s difficult to clean and maintain the grow room with ScrOG, right? Therefore, to make it easier, you can start lollipopping your plants. Lollipopping is nothing but removing all the bottom parts of the plant below the screen so the plant focuses solely on making buds and nothing else. 

Close to harvest

In the end, the results should be something similar if you’ve followed the process to the t. 

Summary: How to ScrOG Cannabis — A Complete Guide

The ScrOG method to grow cannabis is promising to enhance your cannabis yield. When you do this diligently, you will be rewarded with thick buds of consistent sizes.

You no longer have to worry about the lower-tiered buds not growing big enough with this process. 

Just remember to take your time understanding the system and give your plant enough time to recover after training it. And always use high-quality, eco-friendly products for building the ScrOG system to keep your buds pure and organic. 

Don’t worry — the process sounds lengthy but, it is quite straightforward. Take one step at a time, and your cannabis plant will grow buds like never before.









Comments

Noweed
Noweed

Excellent article!!:clap: I have only one question, when is the best time to make the Lollipop in bloom without stressing the plants?

Noweed
Noweed

@CannaScience, Thank you very much!

CannaScience
CannaScience

@Noweed, you can start lollipopping as soon as it flowers by removing a few leaves at a time. Also check out the article on defoliation to know more about this topic https://growdiaries.com/journal/defoliating-cannabis-the-best-method-to-increase-yields

Red_Rockst4r
Red_Rockst4r

:pray::point_left::heart_eyes: