The Screen Of Green (ScrOG) growing method explained
The Screen Of Green growing method, or the hated-by-autocorrect “ScrOG,” is a cannabis growing technique that makes efficient use of small grow spaces. With the help of a screen plants are trained to grow horizontally during the vegetative phase so all of the plant receives equal amounts of light.
In order to ScrOG, a screen is placed over young plants. As they grow, each branch is trained to lie flat, using a twist tie or similar to secure everything in place. Or, one can just use the screen itself, tucking growth tips under the next crossmember as they get tall enough.
The idea is to keep the growing tips evenly spaced and at an even height until most of the screen is covered with vegetation. Things are left alone when making the 12-12 flip to flowering.
Unlike other methods, scrogging does not produce an apically dominant cola. All the flower sites receive equal light. The plant responds by evenly distributing growth hormone all over, producing buds of mostly uniform size.
A minimal amount of plants are used under this technique. In a cupboard of only a square meter, one plant would be all that’s required to quickly fill out the space. The vegetation time is similar to that of an unmodified grow as the plants are not usually topped. Branches that would normally be lower on a plant, receiving suppressive hormones and less light are now trained to lie horizontally and receive the same amount of light as the rest of the plant.
WHAT YOU WILL NEED
- Choice cannabis plants from seed or clones
- 12-liter pots minimum, up to as big as you want to grow
- Screen with 5–10cm spacing (some make their own screen with bamboo stalks)
- Select garden ties or string
- Place mesh about 20cm above pot rim.
- Give each plant a 30cm x 30cm minimum screen.
- Guide new branches under the screen to encourage lateral growth.
- Tie in place, or let the screen hold branches in place.
- Continue to train plants until 70% of the screen is covered, then flip to the flowering cycle.
- Plants will fill up the rest of the space as flowers develop.
- Keep checking for unwanted growth under the screen.
Airflow is important for helping maintain the wet-dry cycle via evaporation and gas exchange at leaf surfaces. Leaf stomata, where gas exchange takes place, are located on the underside of leaves.
As scrogging creates a flat mat rather than avenues between branches for airflow, special attention needs to be paid to efficient air circulation above and below the screen.
Regularly remove fan leaves on the bottom to stimulate growth in the canopy. Remove all leaves from below the screen and check for and remove newly sprouted leaves. Leaves under the screen receive little to no light and risk catching disease.
CHOOSE YOUR GENETICS WISELY
Some genetic and phenotype knowledge will be needed when choosing to use the ScrOG technique, specifically gauging how much of a flowering stretch there is.
Many indica plants barely stretch at all when switching from a 18/6 to a 12/12 light schedule and just fill out the nodes existing at the photoperiod change. A chubby little indica will need to be given almost all the nodes desired for a decent-sized bud.
The opposite end of that scale has sativas that can stretch substantially under the same conditions. Making the flip for sativas at two or three nodes above the screen will still see a satisfying stretch.
Most strains will perform well using the ScrOG method, while some of them will perform outstanding. Give it a try, you won't regret it.