SCROG, short for “screen of green,” is an indoor cannabis training technique. There are many different techniques that help indoor growers maximize their space, but scrogging is one of the most popular.
What is SCROG?
SCROG is a training technique that helps indoor cannabis cultivators maximize their light usage and the number of top buds, or colas, their plants produce. If you leave a single plant in a pot to grow without training, chances are it will develop just one central cola. With SCROG, however, every branch develops into a decent-sized cola. This coaxes out high yields from as few as one to five plants.
Basically, to create a SCROG, growers place a Net —which looks like a large metal grid—about 15 inches above their indoor weed plants. Once cannabis branches grow through the net, cultivators train them to grow outwards rather than upwards by bending the stalks and tying them to the screen.
Scrogging is usually combined with another technique called topping. Topping is basically trimming the tops of your cannabis plants to promote outward growth. When you top your plants, you’re helping them to grow more branches and also become bushier. Then, when you scrog, it helps to expose every inch of those branches to lights. That way, a scrog helps indoor growers use their grow lights most efficiently.
Scrog vs. Sog
The sea of green (SOG) method is another type of growing technique that encourages high yields. In a way, it is the exact opposite of SCROG. SCROG uses a few plants and creates multiple, highly developed budding sites. SOG, however, uses many plants (30 to 40) and focuses on the development of one primary cola.
After clones are given 1 to 2 weeks to establish, they are switched into flowering. This causes the clones to go into overdrive. Their stalks begin to thicken and they start to produce a single, impressive flower.
The SOG technique is quite a bit faster than SCROG. The SOG method is typically used by professional growers who need high yields very quickly. SCROG is better for the average home grower, who wants to get a ton of product out of just a few plants.
While sativas take nicely to SCROG, indicas are best suited for the SOG method. Plants in SOG rarely reach a height of more than 12 inches (30 cm).
The high number of plants used in the SOG method also makes for greater legal troubles in some areas. In most legal states, you can only grow 4 to 6 plants. This makes SCROG a better option for most people.
Overall, you can get a similar yield using both methods.
Why Use The SCROG Method?
Growing cannabis indoors can get expensive because the lights needed to promote healthy growth use a lot of energy. That’s why the SCROG method was invented. With the SCROG method, each budding site receives the same amount of light, promoting many large colas and using the whole grow room most efficiently. Plus, there’s no taller plants to cast shadows onto shorter plants, everything’s more or less the same height in the screen of green.
Scrogging is super useful for indoor growers in both illegal states and those in places with a small cap on the number of legal plants they can grow. For instance, it’s great in Canada where home growing is permitted but most provinces only allow each household to grow four plants. Four plants using the SCROG method will yield more high-quality flowers than four plants without. Plus, all of the buds will be top-shelf quality colas. There will never be soft buds on bottom branches that never fully ripen.
Scrogging is also useful for growing sativas indoors. Sativas, unlike indicas, are tall plants and continue to stretch through flowering. While that’s not a problem outdoors, it is very likely they’ll hit the ceiling if they’re being grown indoors. That’s why many indoor growers use a screen of green, to keep sativas short and to maximize their indoor yields and light usage.
Another benefit of scrogging is indoor growers can bring their grow lights to their lowest possible level. That’s important because light intensity is one of the most crucial aspects of successfully growing weed inside. At the same time, however, if some plants are taller than others, bringing grow lights lower isn’t an option because the tallest plants may get burned.
With the screen of green method, burning taller plants won’t be an issue because they’re all the same height. Just be sure that your grow room doesn’t exceed about 77 degrees Fahrenheit or you’ll risk killing or damaging plants.
Basically, with scrogging, you’re getting the highest quality buds possible for your energy costs, or the most “buds for your buck.”
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.
WHEN NOT TO SCROG
Avoid tucking and weaving your plants too early. It might be tempting to rush ahead, but they’ll only grow well beyond the screen. Training your plants into the mesh too early—during the early vegetative phase—will lead to extra work. You might even run out of room on your grid.
HOW TO SCROG: MAJOR CONSIDERATIONS
Although ScrOG setups can look complex, the technique requires little work. Even if you have limited experience growing cannabis, you can jump right into the technique and produce good results. Just make sure to follow the guidance below, and you’ll be in for a happy harvest.
SELECT THE RIGHT STRAINS
With or without training, growers should always tailor strains to their preferences, spatial limitations, and climate. Some genetics are far more compatible with the ScrOG technique than others. Check out the best characteristics for the job below.
- Stretchy sativas: Sativa-dominant cultivars are lanky, tall, and stretchy in nature. Growers can easily weave their branches and fill out a ScrOG. Of course, you can select smaller and bushier indicas too—just utilise more plants to maximise the potential of your space.
- Strain matching: Growers can cultivate several different strains in the same ScrOG setup for a nice variety of flowers. Try to choose strains that reach a similar average height to minimise the work you have to do.
CHOOSE THE RIGHT POTS
You’ll need to select the correct pot size to optimise your grow. This variable will shift depending on how many plants you want to incorporate into your ScrOG. Consider the following factors:
- Multiple plants: If you want to grow several plants in a smaller space, you need to consider spacing (more on that below). For this reason, each plant will require a smaller pot. An 11l pot will make the most of the space while optimising plant growth.
- Single plants: You can increase the pot size when using a single plant in your ScrOG setup. A 25l pot will give your plant enough room to establish a substantial root system and large canopy.
- Fabric pots: The ScrOG technique greatly improves aeration of the canopy—using a fabric pot greatly increases aeration of the growing medium. The RQS Fabric Pot features a proprietary Aqua Breathe layer, resulting in increased oxygen levels and enhanced moisture retention.
SPACE PLANTS APPROPRIATELY
Growing multiple plants in a ScrOG means you can harvest several of your favourite strains. You can grow high-THC and high-CBD varieties together, and even match plants based on their terpene profiles.
As one of the most important factors when growing several plants, the correct spacing will help minimise mould formation while encouraging the best yield possible. The goal: Fit in as many plants as possible for best results, while keeping them far enough apart to increase light exposure and aeration.
You’ll get away with squeezing four small/medium-sized plants per m² in a maximum pot size of 11l.