The SCROG cannabis growing system

The English denomination SCROG (Screen of Green) would come to be translated as green netting, and the name comes from the fact that with this cultivation system, the plants are literally made to grow by means of a support mesh that serves as support and guide, so that this method allows you to optimize the production of your garden with the least number of plants, something that in many cases can be a great advantage.

We are talking about a cultivation technique used since ancient times in agriculture, today and for decades applied to marijuana. SCROG is a technique widely used in indoor crops, but it has increasingly taken center stage in outdoor gardens, where discretion must be greater every day and this method offers obvious advantages.

This crop combines the SCROG technique with the DWC nutrition system, achieving great results with a single plant
This crop combines the SCROG technique with the DWC nutrition system, achieving great results with a single plant

SCROG and indoor cannabis

One of the great advantages of this system is that it is only necessary, at least, one plant; as the number of them increases, the growth period will be inversely proportional to that of the specimens, that is, if you take 1 m2 of culture as an example and use a plant, you should prolong the growth phase for a long period with help of the mesh as a guide until approximately 70% of the surface is covered (the weeks of growth depend on the genetics, the culture system and the culture parameters). On the contrary, if in that same square meter you use, for example, 4 plants, you will have to make them grow for less time to cover that 70% of the surface you need. As we have been saying, the fewer the number of plants you will need, the longer the vegetative period, so the total electricity bill (of the entire crop, growth plus flowering) will increase proportionally.

SCROG cultivation allows you to optimize crops with few plants, creating a homogeneous canopy. You will see that in the lower parts of the plant(s) little light will penetrate, so it is advisable to carry out a good pruning of the lower parts so that the plants do not waste energy in that area and transfer it to the crowns, where you are interested. to concentrate It must be taken into account that by needing longer growth periods the plants will demand more nutrients, so the use of larger pots will always be recommended.

The objective of the SCROG technique is to completely cover the available cultivation area with a small number of plants
The objective of the SCROG technique is to completely cover the available cultivation area with a small number of plants

How do you grow with SCROG?

Cultivating in SCROG involves placing the mesh above the pot, approximately 50cm, although this may vary depending on the vigor and structure of the plant you are going to grow. This mesh will serve as a tutor and support to guide the growth of the branches so that they "colonize" all the available surface in your grow tent or room. It is important that there is good ventilation in the lower area of the plants, which is why we previously recommended pruning this area. One of the most common ways to guide the growth is to bend the main stem so that it extends under the mesh, so that the side branches and the apex will always go in search of the light, generating a large number of central buds. If you master the technique of topping, you will see that covering the surface is faster than it seems.

Pruning Cannabis Plants

Growers use a wide range of different techniques in order to control the height and size of their plants and improve yields. In this article we tell you several pruning techniques so you can get the most out of your grow!

Since SCROG allows you to largely control the height of the plants and their vigor, this technique allows you to grow highly vigorous and stretching sativa strains, the kind that really stretch in the first weeks after changing the photoperiod to 12/ 12 (flowering), some can even triple their size in this pre-flowering phase. In addition, and taking advantage of this vegetative vigor, you will be able to shorten the growth period considerably. Of course, it can also be very useful for closets or places with low ceilings, where the height of the plants is a problem.

SCROG and outdoor cannabis

The netting or trellis of plants is a cultivation system that has been used for years in agriculture. For example, trellised crops (we could call it vertical SCROG) are a way to control production and the available space, which is often used in cucumber crops or to facilitate automated vine harvesting.

In locations such as terraces, balconies, or those close to small fences (borders with neighbors) the SCROG is a good solution that allows you to contain the height of the plant, also increasing yield and minimizing prying eyes. In mother soil, bending the central apex of the plant or pruning it with the corresponding training pruning is a good alternative to grow sativas or sativa-dominant hybrids, allowing height control and increasing yields in less space even starting cultivation in early spring.

As the branches develop, their growth is guided through the holes in the mesh.
As the branches develop, their growth is guided through the holes in the mesh.

Advantages of SCROG

  • Low number of plants
  • Fewer plants to maintain
  • little height required
  • Homogeneous maturation and caliber of bud production

Disadvantages of SCROG

  • Long period of growth at 18/6 (increase in the electricity bill)
  • Increased use of fertilizer and larger pot size (optional but recommended)
  • Depending on the system used to mesh the plants, it is not possible to move the pots (only if we put individual mesh per pot, normally used outdoors)
  • Difficulties to water on certain occasions (flood irrigation or automatic drip irrigation is recommended)

Final tips

  • Using an Irrigation System or a Grow Tray: Sometimes it can be really difficult to water your plants once the entire canopy is built, so a tray that allows for flood irrigation will make things much easier for you. The use of automatic irrigation systems will also greatly facilitate the maintenance of plants.
  • Change of photoperiod: you should bear in mind that most commercial hybrids double - at least - their size once you change the photoperiod to flowering, so do not overdo it by growing and entangling the plants. As a general rule, it switches to flowering when the branches have covered 70% of the mesh (a little more if you see that the growth of the plant is slow, a little less if you are dealing with particularly vigorous plants).

Thanks to this system, a larger crop area is covered and the light received by the plant is better used
Thanks to this system, a larger crop area is covered and the light received by the plant is better used

  • Cultivation with clones: if you use cuttings of the same variety, you will ensure practically identical growth of the plants and the same maturation date. On the contrary, if there are parts of the seeds, there may be differences, especially at the time of harvesting, resulting in something laborious in some cases to be able to harvest the earliest plants. However, it is totally feasible to do so, although you should take it into account to facilitate the harvest.
  • SCROG outdoors: outdoors, the application of this technique is somewhat different, since the most common is to SCROG with one or - at most - two plants, so there will not be that much difference when using seeds or cuttings. The main thing to remember here is that you will need to take the cuttings outside much later than you would plant the seeds so they don't start to flower, around June in the Northern Hemisphere. For this reason, and starting with seeds that are also especially vigorous, you will be able to cover a much larger cultivation area than in the case of using clones.

As always, you can leave us a message if you have any questions or comments that you want to share with us and the rest of the readers, we will be happy to answer you. We wish you a happy growing and, as always...

Happy harvest!


The articles published by Alchimiaweb, S.L. are reserved for adult clients only. We would like to remind our customers that cannabis seeds are not listed in the European Community catalogue. They are products intended for genetic conservation and collecting, in no case for cultivation. In some countries it is strictly forbidden to germinate cannabis seeds, other than those authorised by the European Union. We recommend our customers not to infringe the law in any way, we are not responsible for their use.

Comments in “The SCROG cannabis growing system” (9)

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mike 2020-04-28
you using a yellow LED for these plants?!

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Klitzy 2019-02-14
My plant is just about finished flowering it has nice buds that are super sticky and dence but when I check the trycomes there still just milky and it kinds seems like it’s just frozen in its state just wondering if there’s sumthin I can do or just wait it out

Alchimia Staff

Tim Alchimia 2019-02-18
Hi Klitzy, thanks for the comment and question. Those milky trichomes will eventually turn amber colour if you leave the plant to mature for long enough. That said, many growers prefer to harvest with milky heads, arguing that this is the peak maturity point, and amber heads are oxidised and degraded beyond their best, while clear trichomes have yet to come to maturity. It's up to you, but if you want amber, you'll have to wait it out! All the best and happy harvesting!

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Mathieu 2018-10-10
Hello, i wanted to ask about the tucking and bending technique , how you guide the branches? Thanks for sharing

Alchimia Staff

Tim Alchimia 2018-10-11
Hi Mathieu, thanks for your question. It's important to start guiding and tucking the branches when they're still bendy and flexible, and before they become hard and woody. Then it's simply a case of being very gentle and careful, trying not to bend any branches double, the best advice I can give is to go slowly, if a branch won't bend all the way to where you want it to go, then bend it halfway, fix it with a tie and then the following day try and get it into the desired position. Usually all the bending and tying is done before flowering begins, and during the stretch period at the start of flowering, which is often when its most useful. I hope that's a help to you, happy growing!

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Medical Marijuana 2018-06-21
Very useful article. Through reading this lot of information about scrog of Marijuana and its helpful.

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Lumpy 2018-05-27
If im scrogging outdoors, for height/stealth reasons, i don't have as much control on when the plant starts too flower, how long do i keep laying branches down for? As my screen might never get full as i cant control the light cycle...

Alchimia Staff

Tim Alchimia 2018-05-28
Hi Lumpy, thanks for your comment and question. It depends on where in the world you are growing and at what point in the summer your plants will be triggered to flower. Here, at around 43ºN, I've calculated that around 15th August is the moment when my plants will have enough natural darkness (over 14 hours) to trigger flowering, so I stop any pruning about 2 weeks before that point to allow the plants to recover before flowering, although you could probably keep on scrogging for a bit longer while taking a lot of care not to damage anything, which could stress the plants, set them back and eventually delay harvest. I hope that's helped, all the best for the season ahead and happy growing!

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Sleepy Is an Alchimia client 2017-12-28
When is the best time to put the screen up? I have three plants, so far, in a 2ft x 2ft x 4ft tent. Two are sprouts about 3 inches and the other is germinated in a peat plug and is starting to root so it'll be behind the other two in growth, not to mention another 2 that are germination in water and havent been added to tent yet, anyhow, is it too early to put a screen up or should I wait till they get about teenage size? Any help is appreciated. T.I.A.

Alchimia Staff

Tim Alchimia 2018-01-02
Hi Sleepy, thanks for your question. First you need to decide at what height you'll position the mesh screen. To make things as comfortable as possible you'll want to fit the screen before the biggest plants reach that height, but not too early in the grow as the net will make your access more difficult, so there's no point in putting it in there before it's needed. Depending on the genetics being used, personally I'd do some apical pruning at the height where I want the plants to branch out and once I started to see new growth and significant branching I'd fit the screen at the appropriate height for the new branches to grow through. I hope that's some help, happy growing!

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Allen 2017-06-08
I'm 6 weeks into veg and want to scrog. I have 4 plants but they're not giving hints on sex. Any advice

Alchimia Staff

Dani Alchimia 2017-06-12
Hi Allen, It is not unusual that plants do not show their sex until the start of the bloom period, do not worry about that. Normally, with the Scrog technique you'd only use clones or feminised seeds, so you make sure that you won't have to remove any plant once into bloom. The Sog system is much easier if you're using regular seeds. If your plants already have the mesh and are ready to bloom, simply switch to 12/12 and remove any male asap. Once removed, fill the available space with your remaining plants. Hope it helped!

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James Beck 2017-04-06
Can you grow outdoors; in single pots, with the same satisfaction/results ? Thx.

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Tim 2017-03-21
Will it be ok to scrog plants grown in a nft tank .the thing is I got 3 seedlings mazer feminised and 2 monster clones taken from flowering plants they have all rooted and are getting in to veging but there gona be all different heights if left alone so I'm thinking of scroging them get a bed of tops same height and flower Does anyone no if this makes sense thanks tim.b.

Alchimia Staff

Dani Alchimia 2017-03-22
Hi Tim, No problem at all, you’ll have a more uniform canopy and light spread will be improved. It is a great method to use when you grow strains with different growth patterns (much better than the SOG technique if that’s the case). Hope it helped!

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