One of the most popular methods to boost the productivity of a grow room or grow tent is to use the SCROG technique (an acronym for Screen of Green). The lower light power used when indoor growing was just becoming popular, created a necessity to optimize the buds’ exposure to light, giving rise to this popular method.
The sun, being a potent light source located far away, delivers similar light intensity to both the top and the lower branches of the plants. However, when you grow in an indoor tent, it is essential to remember that the grow light is a much less potent source that is placed close to the plants, creating a significant lighting difference between the top and lower branches. Hence, it’s not sensible to grow tall plants indoors. The SCROG method helps achieve even exposure across all the buds of the plant.
What is SCROG?
The SCROG technique involves using a mesh suspended over the pots. As the plants grow, the stems are passed through the mesh, encouraging horizontal growth. The goal is to evenly cover the entire trellis to obtain a green screen filled with buds which are all at the same level.
Bending over the taller branches triggers the distribution of auxin, a hormone which is normally found at the central tip. This inhibits the growth of the side branches, turning the “cola” into the main tip.
This phenomenon is called apical dominance. Each time a branch is bent so its height is aligned with that of the others, auxin quantities are distributed more uniformly across all branches of the plant. Consequently, every upper bud gets a higher quantity of auxin and competes to become the main cola, and thus the branches develop larger flowers.
In a nutshell, instead of growing one large central bud and several small ones on the side branches, the plant develops several large buds on multiple branches.
How should the space distribution in a SCROG setup be calculated?
Screen of Green cultivation requires fewer plants per square meter than usual, although these should be grown in larger pots. This technique requires an extended vegetative growth phase so there’s enough time for the branches to be weaved through the mesh. However, this can be shortened by using substrates that enhance the plant’s metabolic processes like coco coir, expanded clay, or rockwool (for hydroponic cultivation). Aeroponic systems can also be used, which often result in explosive growth (which is exactly what’s needed for this training method).
Best cannabis strains for a SCROG setup
The SCROG technique requires vigorous strains with abundant side branching. Hence, it’s best to select genetics that develop large branches and produce lots of buds.
Sativa strains and hybrids with more of a sativa dominance are the best options for the SCROG technique, as they grow vigorously and usually develop a good number of branches.
Pure indica genetics that produce a single central bud are more suitable for SOG (Sea Of Green).
The best strains for the SCROG technique include:
- Many current American varieties with Gelato genetics, like Pisthash; Girl Scout Cookies genetics like French Cookies or Fortune Cookies; OG Kush genetics; or a combination of the three, as in Straw Boujee.
- Sativa-dominant strains like Super Silver Haze, Amnesia Haze, or Jamaican Dream.
- Hybrids like Cheese, Critical King, or Great White Shark.
What is required to grow in SCROG?
As mentioned earlier, the SCROG method requires fewer plants and a longer growth phase than a regular grow. Using this technique, one square meter can be covered with between one and four large pots.
Materials needed for growing using SCROG
Implementing this technique is simple if you have the right elements:
- Pots
Large fabric pots are best for this system. If you’re planning to grow a single plant per square meter, choose a pot between 25 and 30 liters. If you choose to grow between two and four plants, pots ranging from 11.5 to 19 liters will suffice.
- Mesh
A mesh is required for this technique. This can be made with bamboo stakes, plastic-coated wooden stakes, string, or a SOG net. If you want to make the mesh by hand, we recommend mounting a frame with four wooden stakes and some profiles that will serve as a frame for the stakes or strings.
However, the quickest, cheapest, and most practical option is to use a SOG trellis, which is available in various materials:
- High-strength polyester (for instance, trellis netting). This is a multi-purpose mesh with a medium level of difficulty for assembly.
- Elastic rope (for example, elastic SOG net). This is a durable mesh that’s the easiest to assemble, with a hook at each corner that attaches to the tent bars.
- Nylon (like the Sea of Green trellis). This is the most economical option. It’s single-use and is disposed of at harvest time.
The Dark Room and Dark Street grow tents feature the Webit trellis net as standard, but can also include the Webth rigid mesh on request, making it a great choice for growers considering a SCROG setup.
- Watering lance or automatic irrigation
Once the net has been installed, you won’t be able to access the pots with a watering can, so you’ll need a watering lance kit or an automatic irrigation system to feed the plants.
If you’re using organic fertilizers (undoubtedly the best option to preserve the original taste of each strain), you should opt for a watering lance, since most organic fertilizers and additives tend to block the conduits of the automatic irrigation system.
On the contrary, if you’re focusing on maximum production, the best results are achieved with mineral fertilizers. Hydroponic systems with an automatic irrigation tank are a great option, as they combine the benefits of fast and vigorous growth with the advantages of automated irrigation.
How to set up a SCROG grow?
Here is a step-by-step guide on how to grow using the SCROG technique:
- After germination, once the plant has outgrown the small pot, it should be moved to its definitive pot.
- Once it has developed more than three nodes (these are the areas of the stem where the leaves grow), you can cut the tip of the plant as if you were performing topping.
- Removing the apical bud of the plant will generate two branches at the node below the cut and will strengthen the growth of the secondary branches.
- A second and third pruning on the main branches can be performed after a few weeks to generate more branches.
- The next step is to start weaving the plant through the mesh, which should be placed at a distance of 30 cm from the plant). When the plant reaches the net, start weaving the branches. New branches are flexible and will adapt well to this maneuver. The goal is to encourage these and the main stem to grow horizontally.
- Sativa-dominant hybrids and pure sativa strains should be moved to the flowering stage when they’ve filled half of the net. However, you need to wait a little longer with indica strains (until they’ve filled 70 to 80% of the net).
Benefits of growing using SCROG
Some of the benefits of using this technique include the following:
- You can get a higher yield in a grow tent or grow room.
- There’s better control of the plants’ height, which is especially useful with sativa strains or with plants that stretch in excess.
- It improves the buds’ exposure to light, which leads to a top quality yield.
- It’s particularly suitable for growing in limited spaces.
But not everything is a walk in the park… The SCROG technique…
- Requires some growing experience, as well as good prior knowledge of the strain so you can anticipate times and plant development.
- Lengthens the growth phase.
Grow with SCROG outdoors
The SCROG method was designed so that the light from the weak grow lamps from the past could better reach the buds. However, outdoor growers have also managed to make good use of this technique. The benefits of using this method outdoors include the following:
- It leads to a large production of high-quality buds instead of a large cola that is more likely to suffer from fungi and mold.
- It facilitates the cultivation of very large plants in a discreet manner. The plants don’t rise above garden fences, and the crop is harder to spot.
- In case of rain, a SCROG grow is easier to cover than tall and heavily branched plants.
- In greenhouses, it maximizes the available space and facilitates air circulation.
When setting up the net, bear in mind that the recommended pots for outdoor use are larger, between 40 and 50 liters, so the net must be placed 60 to 100 cm above the ground depending on the height of the pot.
A four-legged structure must be set up to hold the net in place. Many growers succumb to the temptation of using metal chicken wire, or metal construction nets that are easier to set up. However, this isn’t a good idea because, in the summer months, the sun will heat the metal, eventually affecting the branches.
Autoflowering strains in SCROG
The short growth phase of autoflowering plants doesn’t allow for a SCROG setup. Moreover, very few autoflowering strains respond well to topping. Therefore, this type of strain is out of the question when growing using this technique, which is known as Screen Of Green, SCROG, or Green Screen.
We hope you’ve found this article useful, and we invite you to leave your comments below with any contributions, questions, or anything else that comes to mind. See you next time!
