Training cannabis plants enables growers to increase yields, reduce pathogen risk, and improve the vibrancy of their crop. ScrOG—or screen of green—is a training technique that forms an even and horizontal canopy. There are myriad benefits to creating this botanical structure.
What is the scrog technique?
Left to their own devices, cannabis plants grow taller than they do wide. The ScrOG technique aims to bring the lower branches up and the upper branches down, stretching them across an evenly distributed plane. By placing a screen above the growing medium, cultivators can weave branches through the mesh as plants grow and mature. By redirecting individual branches and running them lengthwise across the screen, growers achieve a flat horizontal canopy.
Advantages of growing cannabis in a scrog
But why ScrOG in the first place? Well, the technique offers plenty of advantages, including:
- Light exposure: A ScrOG canopy receives even light exposure. Untrained cannabis plants feature one main cola that rises above the rest of the plant, meaning the light rig must remain above this point. In contrast, the lighting rig can hang directly above every flower in a ScrOG setup.
- Yield: Because each bud site receives adequate light, they maximise their photosynthetic potential, leading to an increase in size and resin production. This level of training also transforms the main stem and central cola into a multitude of both.
- Aeration: The horizontal screen of green receives adequate airflow above and below the canopy. The addition of a fan will further enhance this benefit, reducing the risk of fungal pathogens.
- Maximise space: Many growers manage to obtain a larger yield from a single scrogged plant in a small space than with numerous smaller, untrained plants. Covert home-growers can maximise their output with this method. Cultivators can even train several plants and merge them into a single ScrOG.
When to scrog
You’ll start to guide your plants through the screen as soon as they start making contact with it. We recommended positioning the screen around 20cm above the base of your plants, so their rate of growth will determine when exactly you start to ScrOG.
Start the “tucking” process as the apex of each plant begins to grow through the screen. Wait for each tip to grow 5cm above the screen. Proceed to tuck each individual shoot under the screen and direct them through the next square away. Tucking will lay the foundation of the ScrOG process, so be mindful of the direction you want each branch to grow towards.
Continue this process throughout the vegetative phase. Switch to a 12/12 light cycle to induce flowering when the screen becomes mostly filled.
Continue to tuck and weave each branch over the next 2–3 weeks as your plants begin to stretch. This increase in growth will allow you to fill out the screen before your plants enter the true flowering stage and slow their growth.
Why do many growers prefer single plant ScrOGs?
Ease of providing individual plant care – When 2 or more plants are placed under a single ScrOG net, those plants are typically treated the same out of necessity. Growers have trouble getting to plants at the far reaches of the grow. All plants are treated the same despite their strain maturity level or health.
Simple to move around if necessary – If you need to pull a plant from a grow for any reason, you need to cut the net and remove it, leaving remaining plants unsupported.
Improved light distribution – Growers can rotate, custom adjust heights, plants grow at different rates and mature a different rates.
Easy to remove troubled plant from grow space, lowers risk of damage to remaining crop
Easier to water and flush
Allows gardener to harvest plants individually at precise maturity
Eliminates crawling under nets/wire mesh
Wheel chair / handicap accessibility
Irrigation equipment accessibility
A single plant can be scrogged at an optimal time in its growth cycle. Otherwise, only the most aggressive growing plants enjoy the full benefit of Screen of Green.
First time growing with the SCROG method?
The extra effort required with the SCROG method can deter growers from trying it. If you haven’t tried a cannabis SCROG before then maybe it’s time to give the SCROG method a try. Once you have set up your screen it’s only a few minutes of daily effort to tuck branches/stems underneath the netting. The results can be spectacular with heavy yields from low numbers of plants. It may change the way you grow in the future.
When and how to start scrogging cannabis plants
Many SCROG growers prefer to top (or FIM) their plants to amplify the bushy characteristics which are so well suited to scrogging. This means cutting off the main growing tip usually between the 3rd and 5th node during vegetative growth of feminised seeds.
You may wish to give the plant a week or two of additional vegetative grow to recover before switching the plant into flowering. However, if you need to fill a large screen with a single plant then you may wish to ‘veg’ your plants longer. Much depends on your personal circumstances.
Longer periods of vegetative growth suit growers who:
- Are growing low-stretch strains such as Indica dominant hybrid seeds. In order to fully fill a SCROG screen/net you may need to give longer periods of veg growth to these plants. Note that pure indica strains can be particularly tricky to work with in a SCROG. The overall plant structure isn’t suited, stretch is low, branches can snap and the broad figured leaves allow little light penetration.
- If you have a large SCROG net to fill, or if you are using just a single plant you may prefer to use longer periods of vegetative growth.
- If you have a large distance from the growing container to the screen/net you may prefer longer veg periods.
Conversely, those with a small screen, or those with very stretchy sativa varieties will lean towards shorter veg periods. Once you gain some experience in your own grow room you will soon be able to fine tune your grow method to reach new harvest quantities. If you want to know our very best yielding cannabis strains look no further.