24th Feb 2013 No Comments »
LST or Low stress training(light stress training) is a way to grow your autoflower plants and maximize their output yield while simultaneously decreasing the vertical space required to grow and maximizing light usage.
LST stands for Low Stress Training and which means that you are training your plants with the least amount of stress. There are also High Stress Training methods like Topping and Pruning but they are not for autoflowers as they tend to stunt the plants growth for a while and for autos you can’t take that risk as you have a set time period when you plant will finish its life cycle with or without that stunning.
If you perform LST you can get many top buds from one auto plant and all of them will be of the same size and density and you will get much more grams per plant as when you let the cannabis grow one big main bud and small side colas. Usually Autoflowering cannabis produces one main cola at the very top of the plant, all the side branches have weak light penetration and they stay small producing small flowers. There are also some autos that can produce one big cola and almost no flowers and resin on side branches.
How and why autoflower LST works?
Cannabis plants are made to produce as much branches and leafage as they can and their main goal is to create more flowers that can collect pollen and produce seeds. Flowers are usually created at the tops of the main shoots and the largest amount of flowers are at the main cola that stretches towards sun to make the most out of all the sunlight it can get. In nature Autoflowering plants are made to produce one large bud with some smaller buds along the sides. Because the main steam is the one who gets the most sun it will produce the most amount of flowers that can potentially produce seeds and these seeds will reproduce new ganja plants in the next year.
All thisl process is driven by cannabis hormones called auxins.
These Auxins can be found throughout the entire plant but the biggest amount is at the top of the main shoot that is the closest to the light source. Auxins are there because they help cannabis plants to grow and where the most auxins are the most vigorous growth happens. So if you train your main shoot down and it is at the same height as the other branches then the autoflowering cannabis will start to send those auxins at every shoot that is closest to the light source and they will start growing faster. As you trains those shoots that have grown upwards you trick your auto in thinking that it’s main shoot is gone and it will try as much as it can to grow those other branches to maximize the chances of survival as in nature the tallest and most powerful plant with the most flowers will probably catch the most male pollen and produce biggest amount of seeds so it will produce the greatest amount of offsprings.
There is no point of training your plant if you don’t understand this and when you do understand the principle of the Low Stress Training you can do it in a way you feel the most comfortable and get the result you want.
Where to use LST?
You can use low stress training indoors and outdoors and it will definitely increase your yield no matter what environment you are growing autoflowering ganja in. Autoflower LST is better indoors as it increases yield and maximizes space but outdoors growers usually have unlimited space so the only thing is that with low stress training more buds will get maximum light and you will have even canopy not just on big main cola and a bunch of small ones.
When to perform LST on you autoflower?
Autoflower growers have two options when to perform LST.
They can LST their plants from the beginning with a mindset of maximizing yield and their grow area. This method is usually performed by growers who have grown a crop or two and know that LST can help their overall yield and they can get more bud from one plant by performing LST rather than letting it grow how nature intended it. This planned low stress training can be done all the way from the plants start to the last weeks of flowering and also can be done at the time when the autoflower cannabis is growing fastest at the first weeks of flowering period.
- The first stage when you can LST is at the very start of your plants life cycle when the first or second true leaves are fully grown. At this stage your plant tend to grow only straight up and you can start to train it to get multiple tops. This technique when started at the young age will yield the best results and are usually done deliberately with an end goal of maximal efficiency.
- When you don’t start LST your autoflower at the early stage the result would not be as good as when you start from the beginning, but it will still massively improve the performance of the plant. Second stage when growers usually start to LST autos is at the first weeks of flowering or a week before flowering period when a cannabis plant is growing most vigorously and producing the most branches.
When a grower sees that his autoflower is getting out of control and will soon outgrow its grow area he/she needs to do something that will help to train that plant. This option is a very common occurrence between new growers who can’t or don’t anticipate how high their cannabis will grow and don’t train those plants from the beginning. At this stage autoflower is usually more mature than it should be to perform LST most effectively, but you can still do it and it will still be helpful and can save you from increasing grow space or performing High stress training.The only thing that is different at this stage is that the cannabis plant is mature and it will be difficult to train it as it is strong, hard to bend and usually inexperienced growers will force the plant too much and it can fold over or even break.
Why perform LST on autoflowers?
There can be many reasons why you should LST your cannabis plant and I will try to include as much as I can, but there may still be some left out reasons that I have not stumbled upon.
get light to dense buds
Indica dominant autoflowers usually have very dense buds and some kind of LST is necessary to get more light to those dense buds. If no low stress training methods are performed all the buds don’t get the optimum light from one light source.
If you have this problem you can put more light sources around the plant and then maybe LST will not be necessary for you.
get light to lower branches
Getting more light to lower branches will increase your overall yield and for autoflowers this is particularly good because usually growers produce them in small places and want to maximize the grams they get from that space. Outside grown autoflowers are also good candidates for LST as they tend to look like a romb not a triangle and lower branches don’t receive optimum amount of sunlight in the middle of the day that makes them small and they don’t produce reasonable amount of bud.
The overall yield of autoflowering plants can be increased a great deal when you perform Low stress training as more of your plants leafage will get light and will produce more food for the plant so it will grow faster and you will get much more buds that will be denser and the end yield will be considerably bigger.
Minimizing vertical space
Many autoflower growers has a limited vertical space where to grow their plant and with LST you can increase horizontal growth and get more yield not stressing your plants. This usually happens when growers overestimate the strain they bought and can be avoided by buying short autoflower seeds.
Sometimes when autoflowers don’t receive enough light they tend to stretch and it can be a bad sign for growers who want dense buds and those who have limited space. Avoiding autoflwoer stretching can be done by providing more light in combination with LST. If you give more light to your auto it will grow more branches, bud-sides but it will still be stretched and only by performing low stress training you can get much more denser canopy.
SCROG(Screen of green)
Screen of green or also called scrogging is a low stress training method that involves a screen or a net of some sort that holds the autoflower plant buds in place and help growers to tame those wild growing branches. Usually a screen(net) is placed at the top of the plant and when the first shoots get to the screen and grow through it then it is bent back down again. This bending or folding is repeated while the next shoot gets to the screen or the main shoots side branches are again reaching through the screen and at that stage they are again trained back down. This process is repeated as long as you want or as long as your autoflower plant lets you as autos usually don’t grow that long. You should probably do this at the pre flowering stage and continue at the first two to 3 weeks of flowering stage but it can vary a bit as no two species are the same and you can’t compare the fast autos to the super autoflowers. Every grower should evaluate the plants life expectancy and train them till the buds start getting thicker and at that stage the growing tends to stop and cannabis plant starts to focus all its energy on flower production.
There are many variations of the Screen of green training method but I will try to mention some:
1) fully horizontal screen
This is the most widely used method and it is basically putting a screen of some sort horizontal to the ground and training the plant through that screen. You can use any screen or net that has sufficient holes in them for example egg-crates, refrigerator rests , fence pieces and a lot more.
2) Tilted Screen
This is a variation of the horizontal screen where you put the screen horizontal to the autoflower plant but tilt it to one side. Tilting it helps to maximize the space and some growers say that it will also increase the yield comparing to the regular SCROG.
Vertical SCROG for autoflowering plants is the best way to maximize the grow area if you have a one light source at the middle of your grow area. This method basically means that you hang your light source vertically in the center and put a screen around your lamp at a reasonable distance where you can train your autoflower to grow vertically around the lamp.
SCROG for autoflowers – advantages
- You don’t need to maintain as much focus on the plant as regular LST as you can just put the top branch under the next hole in the screen and thats it.
- Screen can support your autoflowers branches and dense buds will not bend over.
- easy harvest
- Screens or nets can be easily reused for your next frow.
SCROG for autoflowers – disadvantages
- Can’t turn the plant: If one side is growing faster or getting more light you will have problems moving the plant around as it is untenable from the screen.
- Requires planning because you can’t just set up a screen on a seedling or almost ready to harvest autoflower.
You can read more about autoflower ScrOG HERE!
Tie down method is the simplest form of LST as it is just taking strings and pulling branches down. In this autoflower training method you need to tie down the most advanced shoot and let other branches take its place and then tie them down as well. This method is really simple and you don’t need any setup to start doing it, you can just put a string around your main branch and slowly bend it down by anchoring the string at the side of the pot. You can perform LST in a controlled way and start with a little seedling and work your way up to the middle of the flowering period to maximizing your yield and used space or you can LST your autoflowering plant at any given moment when you feel like it is time to train that plant.
Tie down method is usually performed in cycles where you start with the main shoot and train it to the ground in a couple of days, then let the side branches catch up and again start training them and then repeat the process until you have achieved your intended result.
Just keep in mind that as the plant gets older it will be increasingly harder to LST it and you will need to do it slower, because small and young autoflower plant have a flexible steam and it can be bent and twisted almost without limits but matured plants have a thick steam that can fold or even snap in half.
Tie down for autoflowers – advantages
- Easy setup – You just need a material that can hold down a growing cannabis plant and a place to anchor it
- No additional planning necessary – this means that you can tie your autoflower ganja plant at any stage of its growth and you don’t need planning for doing it.
- You can easily move your plants around as they are usually trained with strings attached to the sides of the pot
Tie down for autoflowers – disadvantages
- Time consuming – tying down each new shoot can be time consuming as they tend to increase almost exponentially with each LST cycle and you will really need to work at the end of the training cycles.
In my next post you can read a complete guide to autoflower tie down method!
- Always perform LST slowly and don’t hurt your plants. Usually you need to bend it a little each day in order to get the least amount of stress so be patient and don’t overdo it!
- New growers can start performing LST few weeks into growing as the plant will be stronger and you can’t harm it as much.