The SCROG: If you plant a cannabis seed it will grow into a plant. It’s that simple! But aside from the hand of nature, the hand of the grower can manage a plant to improve performance and increase yield and one of the best techniques for doing this is the SCROG (or Screen of Green) method.
The concept of SCROG (and the practice of Scrogging!) is a well known term in cannabis growing, but if you are unfamiliar with this technique it can seem a difficult process and a risk too far to take with your next crop. However, every cannabis grower who takes a leap into the SCROG unknown rarely turns back! Here are some of the most frequently asked questions regarding the cannabis plant SCROG training method:
- What is SCROG/Scrogging (Screen of Green)?
- Why is the cannabis SCROG method recommended?
- What equipment do you need to SCROG cannabis plants?
- What are the best cannabis strains to use in a SCROG set up?
- Does SCROG mean more work in the grow room?
- How high should cannabis plants be before they are scrogged?
- What is topping and pruning and why is this necessary for scrogging cannabis?
- How do you train a cannabis plant in a SCROG grow?
- Will bending and twisting branches damage the cannabis plant in a SCROG grow?
- Can you SCROG Outdoor Cannabis Plants?
- Will SCROG increase yield?
1. What is Scrogging (Screen of Green)?
Scrogging is a cannabis plant training technique which uses a ‘screen’ suspended above the cannabis plants. Through this screen, cannabis stems are weaved (the process is also known as tucking) through the mesh as the plant grows in order to promote horizontal, rather than vertical, growth. Over time, this will produce a canopy that covers the mesh, exposing more bud sites to light and providing an even cover of flowers, producing a sea of similar sized substantial buds.
2. Why is the cannabis SCROG method recommended?
There are three main benefits from applying the cannabis plant SCROG training method to your plants – space, light and air. The first is the maximization of space, especially in a grow tent. The method allows the grower to grow fewer plants but get more bang for the buck in terms of yield. The other advantage of the cannabis SCROG technique is the improvement of light exposure that the plants receive when compared to traditional growth methods where the concentration of light produces fat buds at the top of plants, with those on the lower branches declining in size and density. Finally, this method of growing ensures better airflow circulation amongst the plants’ branches, which minimizes the risk of mold.
3. What equipment do you need to SCROG cannabis plants?
The essential piece of kit is the ‘screen’, which is actually a net, with wide holes allowing the grower to weave cannabis plant stems through and encourage them to grow horizontally. The screen is cheap to buy and commonly available and comes with attachments allowing it to simply attach to the poles of a grow tent. If your grow space isn’t a uniform size it’s just as easy to make one (large holed plastic fence wire can be cut to size and held in place with cable ties). Many scroggers like the method as it allows maximum yields from the minimum amount of plants – one or two plants (in big pots to maximize root room) can easily fill a grow space by following the cannabis scrogging technique. Another very useful piece of equipment is some thick, flexible gardening twine for holding branches in place during the SCROG process.
4. What are the best cannabis strains to use in a SCROG set up?
This technique can be applied to most types of cannabis plant, and it is particularly well suited to sativa varieties which naturally stretch more towards the light (causing space issues in a grow tent). Paradise Seeds strains producing great scrogging results are L.A. Amnesia and Atomical Haze (both sativa varieties), Ice Cream and Durga Mata (indicas) and Opium and Nebula (hybrid varieties). Because of their short lifespan autoflower strains are not recommended for scrogging setups.
5. Does SCROG mean more work in the grow room?
We’re not going to lie to you, the SCROG cannabis growing technique does require some extra management! The aim of Scrogging is to evenly distribute the buds across the growing space and this requires training the cannabis plant. As the plant is a living thing that just wants to grow, this means the grower has to be on top of the management and dedicate some time to weaving those stems to ensure the canopy develops evenly and maintains the same height across it. Nevertheless, the extra effort is worth it when harvest time comes.
6. How tall should cannabis plants be before they are scrogged?
It depends on the set up, but a good height for cannabis plants to start being scrogged is 25 – 45cm.
7. What is topping and pruning and why is this necessary for scrogging cannabis?
In order to promote horizontal growth through the cannabis plant SCROG method there are a couple of steps which are required to help coax cannabis plants in the right direction! The first of these steps is ‘topping’, also known as ‘pinching’, which basically means removing the top of the plant stem. This should be done when you have at least five nodes (these are the points on the stem where new branches start to form). This process will prompt the plant to focus on growing sideways, through its branches and not upwards. Once the strongest side branches are off and running sideways, prune out the scraggly bottom branches so that the plant doesn’t waste its energy on these.
8. How do you train a cannabis plant in a SCROG grow?
Wait until the side branch growth is 2 – 3 cm above the screen before starting the training process. The aim is to evenly fill the screen, so take a moment to work out which direction you are going to weave and make sure each branch is making the best of the space available (ie don’t start weaving all branches in the same direction!) Use the soft gardening twine to hold branches lightly in place after each training session. Once this process becomes established, the plant will lead the way and the method becomes quite intuitive. The aim is to fill the screen as evenly and completely as possible.
9. Will bending and twisting branches damage the cannabis plant in a SCROG grow?
No! Unless you are a real Wreck it Ralph, cannabis plants are incredibly hardy and versatile in the vegetative stage and so long as you’re gentle, whatever bending and twisting you do won’t harm the plants at all. Nevertheless, it won’t feel natural (at first) and there will be moments when any new scorgger thinks ‘Oh no, what have I done?’ as they look at their beautiful plants all mangled like a failed crop circle experiment. Don’t worry though, within a day or two they will recover and be ready for more training! Once plants are in flower it is a different matter and you should avoid stressing them too much.
10. Can you SCROG Outdoor Cannabis Plants?
Yes you can! In fact using the SCROG method for outdoor cannabis plants has many benefits. For a start this technique provides better airflow than a marijuana plant grown the traditional way. In the process this provides an extra level of security against Autumn mold. By controlling the growth shape, a scrogged outdoor cannabis plant is much easier to protect from the rain too. The other advantage is they are far less conspicuous than stand up cannabis plants so camouflaged from nosey neighbors!
The obvious difference is that unlike the four walls of a grow tent, an outdoor plant lacks natural fixings. However, this is not really a problem as four stakes (which can be as simple as bamboo canes cut to lengths), at the corners of the plant provide a base on which to rest the screen.
Unlike an indoor SCROG, the outdoor cannabis grower needs to take into account factors such as surrounding foliage and access to sunlight (ie will the marijuana SCROG set up have sunlight blocked by the vegetation around it?) As plants will be ready to harvest in September/October, the position of the sun – which will hang lower in the sky in these months than it does in midsummer – needs to be taken into account. As such, setting the screen as high as 50 – 60 cm can dramatically improve sunlight access.
11. Can you SCROG autoflowers?
Scrogging autoflower cannabis plants is not advisable. Firstly, because of the speed of autoflower growth (60 – 75 days from seed to harvest) they will begin to flower (bud) after a month. This means there is very little veg time to establish a SCROG. Secondly, with a limited flowering period, you do not want to be stressing the plant out by training it too hard. Some light LST (Low Stress Training) can be applied in order to open up some of the bud sites lower down the plant to light. However, the Paradise Seeds recommendation is to leave the autos to do their thing and grow normally.
12. Will SCROG increase yield?
A well managed SCROG and a responsive plant will increase yield due to the extra amount of space the process