Screen of Green Pruning SCROG Method for Cannabis Production

Screen of Green Pruning SCROG Method for Cannabis Production

Screen of Green Pruning (SCROG) Method for Cannabis Production

Professor DeBacco

Productive Indoor Method
Screen of Green (SCROG) is very productive and easy way to grow indoors when the number of plants may be restricted based on laws.
Not to be confused with the Sea of Green method (SOG) which has more plants and does not involve training
A screen is typically used to support the plants.
While may not be a natural pruning method it can maximize plant production.

Screen Mesh and Placement
What is a SCROG? What is SCReen Of Green?
A screen is the main character of SCROG that is made of sturdy material (commonly wire) to support the plants canopy.
This screen should have a mesh size of at least 2×2 inches up to 4×4 inches to allow for ease of plant growth and support.
The placement of the screen is determined by the lights used, strain being grown and training design chosen.

Screen Material and Area
Many different types of screen material, some use a plastic netting/mesh and others use stronger material like wire.
Ex. Concrete wire is a good option vs chicken wire
Some growers use 50 watts (HPS) per square foot target for their screen. See the following watts to screen size and light distance suggestions…
400 watt 16-20” away from a 2.91ft x 2.75ft screen size
600 watt 20”+ away from a 3.45ft x 3.45ft screen size
1000 watt 24”+ away from a 4.4ft x 4.5ft screen size

Light Dispersion
To maximize the space and dispersion of the light to determine how close the light can get to the canopy.
Do not forget about air circulation.
Note that distances should be checked with a PAR meter to ensure consistent light intensity across the canopy regardless of your chosen light source.

Plant Numbers
Plant numbers are based on how much space a grower wants to train each plant to take up
However in general the goal is to limit the plant number and maximize the space each plant takes up.
Less plants requires a longer time in Veg.
More plants allows for a shorter Veg. time
As growers become more skilled they can often reduce the number of plants to be grown in the same sq. ft. area.
Typical area for a plant is 1-4sq.ft. depending on duration of Veg and experience of the grower.

Timing is Critical
Timing the flip to flower (12/12) is critical to maximizing the area of each plant.
General rule is to wait until the screen area is about 70-80% full before a grower decides to flip their plants to flower photoperiod.
Exact timing can be partially strain dependent.

Training the Plants
Start by allowing 4-6 inches to grow above the screen height.
This acts as plant material to be trained by pulling the branches back under/on the screen in a horizontal orientation.
Going under the screen is advised as this limits the need for additional support to keep the plants in place but is more difficult is fine mesh spacing is used for screening material.
This is an ongoing process of branch training to direct plants to take-up the empty/gap spaces.
However, keep the pruning to a minimal as you want to have many branches to fill the screen area.

Leaf Pruning
Pruning of leaves should be done if the leaf is shading a bud site since the main goal is to increase the light intensity on the actual buds to help maximize plant production.
However, do so in moderation, especially early in the training process to not further stress the plant and potentially stunt its growth.

SCROG with Clones or Seeds or Both?
Some growers believe that clones are the only way to go with this pruning style and while clones may be a little more predictable it does not mean this method is limited to clone starting material.
Due to the time investment with the training process, if you are using seeds feminized seed would strongly be encouraged but keep an eye out still for that 1 in 100 that will be male.

Do Not Forget About Ventilation
With the establishment of a leaf canopy woven through a screen it is important not to forget about ventilation of the plant.
The screen will often act as a physical barrier so above and below canopy ventilation should be considered.
Sometimes this will require two separate fans even in small spaces.

Plant Hormone Influences with SCROG
Increasing the meristem regions requires pruning with the intention of maximizing the branching of the plant.
Removing the apical meristem (pinching) reduces the natural auxin levels resulting in elongation of side branches.

Link to Lecture Slides: https://drive.google.com/file/d/1FkqaLlvmU13KTEPjqy3FG85Vcq22QYvI/view?usp=sharing

*Due to the description character limit the full work cited for “Screen of Green Pruning SCROG Method for Cannabis Production” can be viewed at… https://drive.google.com/file/d/12pXIOFHFzTzVrLbXBPI0c6LsK-XAyifr/view?usp=sharing