There are many benefits of training Cannabis plants during the vegetative period, allowing a grower to alter the shape of a plant by bending stems to increase Cannabis yields. In this article we break down all you need to know about LST and the advantages of using it as an indoor grower.
There are many different training techniques that can be applied to growing indoor plants, and they range from topping, tying down, fimming, super-cropping, and pruning. Cannabis plants are apical dominant meaning they will naturally grow one tall central point with surrounding side branches due to the growth hormone Auxin. Low stress training allows a grower to manipulate the final shape of the canopy prior to flowering, easily changing the shape and structure of the Cannabis plants.
For many indoor growers producing as much dried flower as possible is often the end goal, so one of the benefits of applying LST is bigger yields. This happens as the lower parts of the plant are now exposed to much more direct light, better air flow, and are encouraged to grow big. The concern over lower, undeveloped popcorn buds that take extra time to trim is eliminated and the plants can focus their energy on large-sized, dense frosty flowers.
Depending on which cultivar is being grown out, controlling how tall a Cannabis plant becomes once flowered can often be difficult. Low stress training is an excellent way to significantly reduce the final height once the plants have fully stretched after the first 3 weeks of 12/12. Sativa dominant cultivars will be the most challenging to control height wise, and indica dominant hybrids will typically double in height, so using LST is an excellent way to utilize the indoor space.
Smaller sized lower buds that struggled to receive direct light can dramatically reduce yields, which is another benefit of Low Stress Training. Not only will there be a better distribution of light for the plants, it will also maximize space for indoor growing resulting in a higher gram per watt conversion. The buds that are produced will be uniform and consistent in size ranging from 1-3 inches.
Low stress training basically tricks a Cannabis plant into thinking the tallest central point has been permanently lowered below the top canopy. The result is the surrounding side branches fight for apical dominance and to be able to produce the primary growth site in replace of the originally tied down shoot. As the growth hormone Auxin is redistributed to the other parts, there will be a surge in growth and an evident change in structure.
Using wire is the most practical way to be able to tie down your Cannabis plants. Garden centers will sell plant-friendly versions that can be easily cut and wrapped around plants. You can use thin metal wire and attach the ends to the holes that have been made around the tops of the plant pots. Be careful not to tie the metal wire too tight as it may cut through the hard wood stems as the plants mature.
Thin wooden bamboo
Once the shape of the canopy has been established during the vegetative period, adding support is now the next step. Using wooden bamboo canes carefully placed around the edges of the pots to avoid penetrating the main root ball, is a brilliant way to support the side branches. Bamboo canes are cheap to buy and will prevent heavy branches from toppling over from excessive weight later into the flowering period.
In order to securely anchor the metal wire to the pots, it is necessary to create holes that the end of the wire can be looped through. This can be a long-winded process, especially if you have a large plant count, so using a hand drill can be the fastest and most practical way to permanently fix the wire in place. If you don’t have a hand drill, a screwdriver or pair of scissors can suffice, however it is far less practical and can be much more work.
For large-sized plants that may have been vegetated for 6-8 weeks that have produced thick side branches, using ducting tape and taping them to your bamboo canes can be a good solution. Plastic cable ties can also work well, however using duct tape can give a tight and firm grip allowing the plants to focus on producing big buds.
When to start Low Stress Training
All plant training should be applied during 18/6 and when plants are in the vegetative stage producing foliage. It is possible to begin LST on seedlings or clones once they reach a height of 6-8 inches with 3-4 internodal sites. How long an indoor grower decides to vegetate the plants will determine how frequently Low Stress Training can be applied, until the desired canopy shape has been achieved.
Low Stress Training step-by-step
STEP 1: Take the plant that you want to use and find the tallest part of the canopy. Using your hand, gently bend the shoot over, and make sure there is plenty of leverage and flexibility without a potential stem break.
STEP 2: Once you have confirmed the shoot can bend with ease, take the metal wire, and gently loop one side firmly around the stem part underneath the top internodal growth site.
STEP 3: Now you can insert the other end of the metal wire into the holes in the tops of your plastic pots. As you do this you will carefully ensure the shoot bending down does so with ease and is facing downwards at an angle.
STEP 4: Loop the wire through and firmly tie, to make sure the bends stay in place and do not loosen up overnight. It is possible you may need to add more slack over the upcoming weeks, so it is a good idea to make sure untying the wire each time is not difficult.
STEP 5: It will take around 3-5 days for the tied down shoot to grow back and begin to grow upwards with a curved shaped stem. Simply repeat this technique as many times as you desire, until the ideal canopy shape and size has been achieved.
When to stop LST training.
Once a Cannabis plant receives 12 hours darkness, it will begin to flower and this is when they can stretch resulting in a size difference of double or even treble their original height. LST should be applied prior to changing timers over to 12/12 and the most important thing is to have established your canopy in advance.
Incorporating other plant training methods such as fimming, super cropping and pruning can have many benefits when used with LST, so always make sure you have plenty of time for the plants to recover and heal from any low or high stress training techniques.
If you want to make the most of LST in your grow, it’s important to know which strains will give you the best results. The autoflowering varieties, for instance, aren’t good candidates since their vegetative period is so short that there’s no time to apply this technique. Here are some other choices that are better for getting the most out of LST: