Screen of Green (SCROG) is a cultivation method where plants are trained to grow through a net. This makes it possible to obtain more crops on the cultivated area with much fewer plants than usual.
It’s a fun and fascinating technique that makes it possible to achieve huge yields with just one plant.
In addition, it is suitable for cultivation areas with low ceiling height, such as cave tents, as the plant growth is directed more horizontally.
Number of plants in SCROG
The number of plants can be anything from 1 to 5 cannabis plants perm2 (1x1m). How many plants you choose does not affect the yield. At the end of flowering, the result is the same regardless of the number of plants; you get the same yield from 1, 3 or 5 plants. The only difference the number makes is the time needed in the vegetative phase before the plant fills out the net.
NB. Even if you get the same yield from 1 as 5 plants per harvest, it is of course not equal in terms of yield. yield measured in time. Since you spend more time in the vegetative phase to make, say, 1 large plant rather than 5 smaller ones, it is all the same more productive to grow smaller plants, since you can flower them more quickly and get more harvests annually (not, of course, for autos that have a genetically predetermined length of the vegetative phase).
To start growing in SCROG, you need a network.
You can buy nets specifically made for SCROG, called SCROG nets, in most grocery stores.
However, the cheapest and best – according to us – is to buy a roll of wire mesh in the DIY store. It is much easier to attach, is stable, does not bend or fold, and does not cut into the plants. It is important that the mesh size is 5-10 cm so that the plants can grow through.
If you grow in a tent, the net is easily attached to the tent poles with strips. If in space you can build a frame of battens for the fixing.
The net should be placed about 20 cm above the pots.
As the plant grows, the plant’s branches are trained to grow along the network to control growth. The top of the plant should always be kept at the same height as the rest of the plant, so that you get a uniform “tree crown”.
This is an ongoing process that continues until the plant covers about 70% of the grid. How long it takes varies greatly from cannabis strain to cannabis strain.
The flowering phase of SCROG
Once this has happened, the vegetative phase changes to the flowering phase. This is started by giving the plant a daily rhythm of 12 hours light on and 12 hours light off. This is only necessary with photosensitive plants and not with autoflowering plants, as the latter flower themselves after an average of 3-4 weeks independently of the circadian rhythm.
At the beginning of the flowering phase, the plant will stretch and fill the last 30%, so that 100% of the area is covered. During the rest of the flowering phase, all the top shoots will be at roughly the same distance from the lamp, which will result in the whole plant receiving the same amount of light and therefore developing uniformly and becoming the same size.
Apart from this, there is nothing special in the flowering phase to pay attention to. They need to be treated and grown in the same way as regular cannabis plants.
Pot sizes in SCROG
If you choose to grow only one plant perm2 with the SCROG method, you should choose a large pot; 18-25 litres is a reasonable starting point.
Furthermore, it should be transplanted several times (from small to progressively larger pots), and expect the vegetative growth period to take 5-7 weeks before the plant is ready to flower.
If you choose 3-5 plants or more perm2, 12 litre pots or so are an excellent choice. The plants’ expected vegetative period here is about 3-5 weeks before they are ready to flower.
What is a good cannabis for SCROG?
Sativa strains are particularly suited to SCROG as they tend to stretch a lot in growth. However, they can be difficult to control at height. Indeed, if you’re not careful, Sativas can quickly grow way over the net, where it becomes a bit risky to get them back into SCROG without breaking the branches.
Conversely, SCROG is brilliant at countering the disadvantage of Sativa height. Many Sativas are not particularly suited to cave tents where ceiling height is limited. The SCROG method provides a good tool for taming the height of Sativa by changing its natural growth pattern from vigorous vertical growth to horizontal.
Sativa’s energetic growth is an advantage in SCROG, as it quickly fills the net. However, it is important to keep this in mind and only fill 50-60% of the net when growing Sativa. Otherwise, it can quickly run afoul of one.
Indica doesn’t have nearly as many side branches as Sativa, and doesn’t stretch quite as far. It can therefore be advantageous to nip the top to create more side branches, or alternatively use more plants on the same m2.
Indica’s more compact structure and growth pattern means that you should fill the net 70-80% before flowering starts, otherwise you risk not using the area/net to its full potential.
Good varieties for SCROG cultivation
Summary: Advantages and disadvantages of the SCROG method
In addition to harvesting the same yield with a smaller number of plants, SCROG has a number of other advantages, including:
+ Watering is much easier; it’s obviously faster to water 5 in SCROG as opposed to, say, 15 plants in a SOG system.
+ The fewer plants there are, the easier it is to maintain a high standard of cleaning. Collection of dead leaves, pruning of side branches at the base of the plant is much easier, reducing the risk of diseases and other problems.
+ The quality of the crops will generally be higher, as it is easier to care for – and you tend to make more effort – if you have few plants as opposed to many.
– More time-consuming than other methods because the vegetative phase is often longer.
– Requires more effort to achieve a good result, as the quantity of plants cannot compensate for the shortcomings of the cultivation.
– Minimal “risk spread” – you are more vulnerable if something goes wrong, as you have no more plants to cover yourself with.
– Hard scalding of the branches can cause cracks and breaks, even if you are careful. It takes due diligence, care and a lot of patience to avoid this.