Not sure if you should be using a SCROG? Do you have a small growing space? Are you growing only 4 plants? Do you have limited access to starting material like seeds or clones? Are you interested in up to 20% heavier yield? Do you want to get the most bang for your buck? Are you trying to grow a large sativa? If you've answered yes to any of these questions starting the SCROG technique may be for you, keep reading!
What is SCROGing?
SCROG is an abbreviation for Screen of Green. It is a high stress training method for cannabis (and many other plants) that optimizes light and nutrient resources by creating a horizontal canopy giving all bud sites to have equal access to resources. This is important because better/equal resource distribution means a better yield.
SCROGing involves securing a screen to a tent then training plants to grow into it. The new growth is tucked into the screen and oriented outwards covering the screen fully. Eventually when flowering starts the buds will grow through the screen (which is flat and even) so all bud sites will receive equal light (instead of central colas getting most of the focus with side buds becoming smaller.
When left to their own devices, most strains will grow in a Christmas tree formation with one main central bud and a bunch of smaller buds down the side. All these small buds are using light and nutrient resources (and are in many cases being wasted on buds that will never fully form/will be a waste of time to trim). This is why topping and FIMing are important for making the plants bushier so they grow into the screen better.
HOW TO SET UP THE SCREEN OF GREEN
- Germinate seeds or take cuttings to create clones.
- Space the plants out at about 1 or 2 plants per square foot, but only one row. Make sure you have full access to all the plants.
- Grow them using 18 to 24 hours of light.
- Once the plants get 4 nodes high, top them by clipping the grow site (which splits the main cola into two sites).
- Add the screen to your grow space, placing it 6-10 inches above the pot. Make sure you can easily access the pots at all times.
- Continue vegging and as the plant starts to grow and poke through the screen tuck it back under (see video below). Your goal is to get the branches to grow towards the edge of the tent one square at a time.
- When the screen is at least 70% full switch to flowering, 12 hours light and 12 dark. The screen will fill entirely by the end of flower.
- 7-10 days into flowering, remove any leaves and flowering sites that didn’t reach the screen. Keep the underside of the canopy clean going forward (especially great for airflow and preventing mould).
- Finish flowering and harvest.
PROS OF SCROG
-Great for space limitations: SCROGs can be modified for any size garden.
-Bigger yields overall: SCROGing maximizes the canopy so there are is no unused space in your tent or grow space.
-Bigger buds overall: SCROGs grow plants horizontally and no energy is focused on lower buds that get little or no light. All energy is distributed evenly among plants in the light.
-Fewer pots and less watering overall: Fewer pots mean less soil (and more importantly less hauling around and disposing of soil) and less watering. Once the screen is in place you need to be able to access every plant from under it. For example, I used to use 9 of the 10 gallon pots per square meter. In a SCROG I use 2 or 3.
-Fewer seeds and clones needed: Growing horizontally in a SCROG allows you to get the same canopy size with less starting material. See example above--I use a third of the amount of starting material that I did before (and working towards much less).
-Great for all strains: You can SCROG with all strains but sativa varieties especially should be scrogged because they grow extra tall quickly.
CONS OF SCROG
-Slightly longer veg: In a SCROG you are going to keep vegging for weeks until the screen is almost full. When you might normally flip to flower at 8 weeks, in a SCROG you would wait 12 weeks to flower.
-Lots of pruning and training required: SCROG is more advanced and the whole point is to tuck and prune until you have a huge horizontal plant.
-You must use feminized seeds or clones: Because the screen is already in place you won’t be able to sex plants and remove any males as they present themselves.