How to Use the SCROG Method for Bigger Cannabis Yields

The Screen of Green (SCROG) technique is one of the most effective strategies for optimizing space and increasing your cannabis yields. This guide will clearly break down the SCROG technique from beginning to end so you can DIY with ease.

What is the Screen of Green (SCROG)

The name SCROG is just a simple acronym for Screen of Green, defining the method perfectly. It’s a rewarding, low-stress training (LST) method where you use a flat screen or physical net to carefully manipulate the growth of cannabis plants.

The main goal in SCROG training is to horizontally weave the main stem and other dominant branches into the screen netting. This breaks their vertical stretch and spreads the plant canopy evenly.

Why Use the SCROG Method

The Screen of Green method offers substantial benefits for plant yields.

• This flat, uniform canopy tricks the plant into converting what would be small, lower growth into large, primary colas, dramatically increasing your final harvest weight.
• Your grow light energy is used efficiently because it is distributed perfectly to multiple bud sites, meaning you eliminate the risk of undesirable popcorn buds below.
• The improved airflow throughout the plant helps with issues like mould, mildew, and pest infestations in dense growing environments.
• Scrogging maximizes yields in grow rooms with limited overhead space that tall plants easily outgrow.

What is the difference between Screen of Green and Sea of Green

It’s easy to get SCROG confused with its close cousin Sea of Green (SOG)

1. Function: SCROG uses the screen for active training and branch manipulation. On the other hand, SOG primarily uses the netting for simple physical support of the numerous, but smaller, colas.
2. Plant count: SOG aims for a high plant count, sometimes nine to sixteen small plants per square meter. The Screen of Green (SCROG) method uses a low plant count, typically only one to four large plants.
3. Vegetative period: To manage the canopy density, SOG plants rely on a very short vegetative time (2-3 weeks). The SCROG method demands a much longer vegetative time, often four to ten weeks or more, to fully spread out and cover the entire net.

SCROG Setup and Preparation

What strain is best for scrogging

The ideal strain for SCROG is one that naturally stretches quite a bit and responds well to training.

You should look for Sativa-dominant feminized seeds because of their stretching prowess. These genetics will fill the net quickly and efficiently, making your SCROG project much easier to manage.

Generally, autoflowering strains are not recommended for scrogging. These strains have a fixed and very short vegetative phase, meaning they don’t get to fill up very well. For this reason, photoperiod plants are always preferred, as they let you extend the vegetative stage until the net is perfectly full.

Materials needed for scrog

Your basic SCROG setup is straightforward and requires only a few key components.

• Screen or Netting: Options range from flexible plastic pea netting or durable string/twine to pre-made elastic nets or custom-built metal/bamboo frames. An effective grid size for the mesh is typically between 5 and 15 cm.
• Support Structure: You will need a very strong framework—often built from sturdy PVC pipe or lumber—to hold your SCROG net tight and in the correct fixed position above the plants.
• Pruning Tools and Ties: Always keep a pair of sharp, clean pruning scissors nearby for any needed topping or trimming. You will also need to use soft plant ties or string for gently securing stubborn branches into the horizontal plane.

SCROG Technique Step by Step

1. Setting Up the Screen

You must install the screen early in the vegetative phase, ideally before the plant’s tops reach the net. This ensures that the SCROG screen is unmovable once your training efforts begin.

Position your net approximately 20-40 cm above the top of the grow medium. The screen height is a variable you set based on your specific strain’s anticipated stretch and your grow room size.

1. Preparation in the Vegetative Stage

In this phase, your goal is to intentionally create many horizontal shoots where there would naturally be just one vertical cola.

Once your plant has developed roughly 5 nodes, use clean scissors to snip the main stem just above the intersection, which successfully breaks apical dominance. You will repeat this topping process until you have created your target number of main shoots (perhaps eight or sixteen).

To ensure quick recovery, your plant must remain firmly in the vegetative stage (using an 18/6 light cycle) until the screen is between 60% and 85% filled. This longer vegetative growth time guarantees you have the maximum number of potential bud sites spread evenly under your grow light.

1. Training and Tucking

You should begin the tucking process as soon as the plant tips grow about 5 to 10 cm above the screen.

Gently bend the new growth under the net, guiding it horizontally through the next open square away from the plant’s centre. You must strive to fill every square on the net with a single branch, but remember to be gentle because forcing a woody branch too hard can cause it to snap.

The training’s ultimate goal is to form a perfectly flat canopy where all your future bud sites are at the exact same height.

1. Transition to Flowering

This is the final critical step where you convert your vegetative canopy into a flowering screen.

The best time to flip SCROG plants into flower is when the net is about 75% filled. This calculated timing leaves just enough room for the plant to fill the remaining 25% of the screen during its “flowering stretch.”

Pro Grow Tip : Always guide branches sideways until the screen is full.  Then let them grow upward during flower.

For the first two to three weeks of the 12/12 cycle, your plant will aggressively stretch, so you must continue to tuck any rapidly growing branches back under the net. Once the flowering stretch ends, your active training work is complete.

Best Practices for SCROG

Lollipopping/Defoliation

Any growth beneath the screen receives minimal light, so removing it redirects all that wasted energy into swelling your top colas. This essential step is called lollipopping and is performed during the first one to three weeks of flowering, right after the light cycle flip.

Watering and Nutrients

Training can be physically stressful for the plant, so careful management of its needs is key.

You must immediately ensure the plant is well-watered after any major tucking or defoliation session to help it recover quickly.

Because the dense screen obstructs easy access, many growers find success using a drip irrigation system or a convenient long-reach watering wand to hydrate the plants efficiently.

Environmental Control

Airflow is absolutely critical in a dense SCROG canopy setup. Installing oscillating fans both above and below the canopy helps you to maintain constant air movement. Stagnant air is a frequent breeding ground for mould (powdery mildew) and destructive bud rot.

Also, always maintain proper vapour pressure deficit (VPD) for healthy growth. While SCROG filling allows for a higher vegetative humidity of around 60-70%, you must reduce humidity to 40-50% in the flowering stage. This will reliably prevent dangerous fungal issues.

Harvesting SCROG Plants

Because the SCROG screen is fixed, you’ll need to adjust your usual harvesting strategy.

You will not be able to pull the entire plant easily out of the tent, so first, you must trim the screen and then harvest your branches one by one. Only remove the entire SCROG net after you have freed all the flowering branches.

Common SCROG issues and solutions

An uneven canopy is likely to happen when you fail to top early enough or are doing inconsistent tucking during training. When this happens, you must focus your tucking efforts immediately on the tallest branches and quickly prune any lower growth that tries to compete for light instead of spreading.

If you find mould or bud rot developing, this is most often caused by stagnant air and dangerously high humidity inside the dense canopy. To fix this, you must immediately increase fan circulation, drop your humidity to 40-50% in flower, and ensure you do aggressive lollipopping/defoliation to open up the airflow.

Finally, you need to act fast when you break a branch by applying too much force during tucking. Immediately apply duct tape or plant repair tape to the break, which acts as a reliable splint, and the cannabis plant can usually heal itself perfectly.

Can you SCROG outdoors

The SCROG method is not just for the indoor grower; it works beautifully outside too.

Outdoors, SCROG is used for stealth, keeping tall, stretching strains low and discreet. The screen also serves as a crucial structural support to protect the plant against strong winds or the sheer weight of its massive buds.

Bruno Eastman Cannabis Specialist / Content Writer

Bruno Eastman is a seasoned cannabis cultivation expert with over fifteen years of experience in the Cannabis Seed industry. Throughout his career, Bruno has managed some of North America's top cannabis growing facilities, earning recognition as an authority in the field. His expertise lies in understanding the intricate dynamics of cannabis plants and making the small adjustments that drive successful yields.

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