• Post last modified:May 18, 2022
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Do you know what separates average cultivators with average yields from expert growers with impressive yields? Cannabis training techniques! There are several training methods that a cultivator can utilize to maximize yields, improve the plant’s aesthetic value, and minimize pathogen attacks. These methods are tailored for different cannabis plant varieties to achieve a particular goal. If you are looking to mix space management and maximize yields, you are in the right place. 

The ScrOG method, also known as ‘Screen of Green’ is a training technique that involves stretching cannabis plants’ branches on an even plane. This is done by weaving the branches on a mesh, which allows the bottom branches to shoot vertically, creating a dense, even canopy. The formation allows maximum light penetration and sufficient airflow, leading to multiple bud sites and impressive yield (2 to 3 times the average yield). This piece explores everything you need to know about the ScrOG technique, including setting up the screen, tips on maximizing yields, and how it differs from the Sea Of Green technique. 

What is ScrOG and why should you try it? 

ScrOG utilizes a net or a screen to limit the vertical growth of cannabis plants. The method goes hand in hand with High-stress training techniques, such as topping and fimming. After cutting off the main shoot (not a must), the rest of the stems and branches are weaved through the screen or tied to it to foster lateral growth. The spreading of the branches allows all parts of the plant to get access to optimum light, leading to the development of healthy flowers in multiple bud spots. The screen is made from string, hemp cord, or plastic nets. 

At first, scrogging may seem like a complex technique to master, but once you get the hang of it, it will be your go-to yield-boosting method. Here are some of the advantages of using ScrOG.

screen of green technique

Light penetration: Scrogging creates an even canopy that allows light to reach all the branches. By eliminating apical dominance, the rest of the plant gets a fair opportunity to access resources that promote optimum growth. 

Improved airflow: stretching out the plant gives each branch to grow laterally, thus creating a widespread canopy. When combined with pruning, scrogging prevents still air, which is one of the factors that facilitate pathogen infestation and heat stress.   

Increased yields: improved airflow and light penetration improve the plant’s overall health and support higher yields. As the branches are weaved out, the lower branches get a chance to grow up, forming numerous bud sites. A scrogged plant has the potential to produce a yield that you would otherwise get from two or three untrained cannabis plants. 

Space management: scrogging is especially beneficial to cultivators with limited vertical space. The screen puts a limit on how tall the plants can grow. Additionally, if the grow room/box/tent cannot support many plants, you can maximize the yields using few plants and still get the same yields. 

When to ScrOG cannabis plants

Timing is the key to harnessing all the benefits ScrOG has to offer. Introducing the net/screen too early means the plant will at some point grow beyond it, giving you extra, unnecessary work. The plants may grow exponentially, stretching beyond the grid. Waiting too long will require you to force the branches through the screen, which is a lot of hard work that may damage the plants.

The best time to ScrOG cannabis plants is during the vegetative stage as they experience a growth spurt. If you are incorporating training techniques like fimming or topping, wait until the plants have developed at least 5 nodes and then give them a few days to recover before introducing ScrOG.

When to stop scrogging cannabis plants

Scrogging is done during the vegetative stage and 2 to 4 weeks into the flowering stage when the plants stretch to double or triple their initial size. The right time to stop scrogging is when bending the stems and branches becomes difficult. If you notice that weaving leads to the destruction of some of the buds, it’s time to stop.

Things to consider before scrogging

Before diving into this technique, you need to prepare beforehand to ensure a successful growth cycle. Here are some of the things you need to consider;

The type of strain: scrogging is more suitable for Sativa strains. The stretchy genetics make them more preferred as they can quickly fill the screen due to their prolonged vegetative phase. This does not mean that Indicas cannot be scrogged, but one needs to extend the vegetative stage to ensure the plants stretch enough to fill the net. For amatuer cultivators, the best bet is to start with genetics that make the experience as seamless as possible, then try other varieties as they gain more experience.

Are you growing one type of strain or multiple?: if you intend to train different strains at a go, choose plants with closely related average height to make fitting them on the screen much more manageable. Scrog allows growers to cultivate several plants with varying characteristics (high THC, high CBD, etc.) using the same or different screen.

Growing pot size:  the size of the growing pot is a significant determiner of how successful scrogging will be. Consider small to average-sized pots if you plan to have one screen for several plants. This will allow the root system to grow well enough to support the stretching of the plant, but not so much that it grows out of the grid. Large pots are designed for solo or dual plants within the same screen. They allow the root system to grow exponentially to support a large canopy. 

Aerated pots: there is no stressing enough about how airflow is essential for cannabis plants, especially those undergoing training. This includes unrestricted airflow around the canopy and in the root system. Invest in well-aerated pots to facilitate optimum airflow, proper drainage, and moisture retention. 

Spacing sweet spot: crowded plants create the perfect environment for pathogens such as bud rot, powdery mildew, pests, and others. A cultivator needs to find the spacing sweet spot that allows them to make the most out of the screen while maintaining a healthy distance.

before scroging cannabis
Ensure you have plenty of room in your grow room for the best results from your plants

The process: How to ScrOG cannabis plants

How to make a ScrOG screen 

There are two ways to approach this: you can either buy a ready-made ScrOG net/screen or make one yourself. It all depends on time, budget, and preference. Here is how to make a scrog screen

  • The first rule is to create a big enough screen to fit your plants. Bigger is always better. With a small screen, the plants will stretch beyond the grid, defeating the purpose of scrog. When working with a small grow room, make or buy a screen that fits the area.
  • Use hemp cords or strings to make your screen (5cm by 5cm per)
  • Make the frame of the screen using pieces of timber. Cut four evenly-sized legs and attach them with screws at the top of the frame. 
How to ScrOG by making your own frame
ScrOG screen frame made from bamboo and wire

Scrogging step-by-step

Finally! It’s time to acquire that much-anticipated knowledge. Scrogging is a straightforward technique that requires dedication to execute for high yields. 

  1. Place and set up the screen 20cm to 50cm away from the base of the growing medium. The proper distance will depend on how stretchy the strain’s genetics are. Place grow lights strategically to supply sufficient light to the plant(s).
  2. Wait for the branches to grow up to the screen’s height and start weaving and bending them as soon as they touch it. Unlike vines, cannabis plants need to be manually threaded through the mesh screen. Each square should hold one branch to avoid overcrowding. Ensure you are not too rough with the branches as they are fragile and can break easily. 
  3. Direct the plants in different directions to create an even canopy that fills the entire screen. Use a soft garden tie to tie down the branches where necessary. 
  4. Repeat the process regularly throughout the vegetative phase. If growing Sativa plants, switch the light schedule to 12/12 once 50% of the screen is filled. The plants will stretch and fill the screen during the first 1-3 weeks into flowering. When cultivating Indicas, wait until the screen is almost full to initiate the transition into the flowering stage. 
  5. Continue scrogging for the first 2 weeks, then let the plants stretch vertically. This way, the blooms will neither be too tall nor too short. 
  6. Once done with scrog, conduct pruning to remove dead leaves and branches. This helps remove unproductive parts of the plants that compete for resources with healthy and bud-producing ones. 
  7. Feed the plants with water and growth nutrients rich in nitrogen during the vegetative phase to facilitate optimum growth. 

How to get the most out of scrogging 

  • Use LED lights in your growing room. They may be relatively expensive compared to HPS light, but they provide an optimum light spectrum and less heat. Follow the manufacturer’s instructions on the best distance to keep between the LED lights and the plants
  • Feed the plants sufficient nutrients so as to avoid a deficiency or burn. Water the plants only when 3cm-4cm of the soil from the base is dry.
  • Utilize aerated grow pots to facilitate airflow, proper drainage, and moisture retention. 

Sea Of Green Vs ScrOG method of growing?

Both SOG and ScrOG are low-stress training techniques utilized to improve yields. Most people confuse these two techniques, usually due to the almost-similar name. However, the two methods have numerous differences highlighted in the table below. But first, what is the SOG technique? This method involves growing multiple cannabis plants side to side as opposed to having one or few (ScrOG).

Due to the high number of plants per square foot, the plants grow in their classical pine-like shape with the light focused on the central stem. In this case, budding focuses on the central cola, resulting in one large bud per plant. The technique aims to reduce the vegetative stage (2 to 6 weeks) and maximize the yields in a small grow space. The canopy of buds is referred to as the Sea of Green. Here is how SOG differs from ScrOG.

Factors Screen of Green Sea of Green 
No. of plants 1 to 3 for every square meter, giving each plant enough space to grow laterally. Some growers prefer one or two plants. 10 to 11 plants for every square meter. The secret is to grow one plant per square foot.
Vegetative stage durationHow long the vegetative stage lasts will depend on how far the screen is placed from the base of the growing container, the genetics of the plant being grown, and how filled you want the screen to be. Depending on whether one is growing from seed or clone, the vegetative stage can be non-existent or last between 2 weeks to 4 weeks. 
Apical dominanceMost plants are topped or fimmed to eliminate the apical dominance before they are subjected to the screen of green. If not, weaving the plants allows the lower branches to get equal access to light, thus countering the apical dominance.  SOG takes advantage of apical dominance to produce a healthy, big bud on the central cola and few, less healthy ones at the bottom.
Yields Yield per plant is significantly higher than the average yield. Yield per square meter is higher than the average yield
Suitable cannabis geneticsBest-suited for Sativa plants due to their stretchy nature although not limited as one can also use Indicas Perfect for Indicas due to their short stature and short flowering period.
Commercial or personal growBest for personal growth to achieve the most out of each plant but is also utilized by commercial growers.Works best for commercial growth for cultivators who want high yields at an accelerated speed. 
Legality An ideal technique for states or countries with a legal limit to the number of plants one can cultivate.The high number of plants can lead to legal issues in some countries/states.
Compatible training techniquesCan be paired with topping, supercropping, lollipopping or fimming for higher yields.Can be combined with the lollipopping technique for better yields.

There is no way to determine the best method. The decision on which one to utilize is based on a cultivator’s preferred number of plants to work with, the legal status of cannabis, the type and size of growing room, and the available time. 

Can you ScrOG outdoors?

Yes plenty of growers use the screen of green technique outdoors. However it is most often used indoors as it allows a plant to absorb more light from a static light source. Outdoor ScrOG grows do not necessarily need to obtain a flat canopy in the same way that an indoor ScrOG set-up does, this is because the sun moves throughout the day and therefore the plant will naturally get light from all sides.

When using the ScrOG growing method outdoors many growers opt for a more natural growing shape by simply using a wire mesh or net wrapped over a plant such as in the image below.

outdoor scrog grow

Top 3 strains for scrogging

Some cannabis plants are naturally suitable for the Scrog technique thanks to the flexible branches that can be easily bent. Said strains can be tucked repeatedly to achieve a widely spread, even canopy for maximum yields. The strains highlighted below are not only flexible but have the ideal internodal distance necessary for a successful Scrog

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