What is low stress training (LST)?

A cannabis plant that has undergone low stress training
July 21, 2020

Low-stress training is one of the most straightforward, safest, and effective ways of growing marijuana. It is all about changing and maintaining the shape and structure of cannabis plants – most notably, the canopy. And to do that, you have to bend and secure the stems. It’s as simple as that. No need to damage the plants or drastically change your growing setup.

The result? Generous yields composed of fat, dense, and potent buds.

For most growers, it is important to get the maximum result from cannabis seeds and LST is an effective and efficient way of growing marijuana.

But to ensure the success of the procedure, make sure you know precisely what to do and what to avoid. In this article, we outline all you need to know about boosting yields by low-stress training marijuana plants.

Many growers can spend years figuring out how to grow marijuana in the most effective way. However, this guide should help to save time and effort by introducing a different technique for growing marijuana which is maybe new or unfamiliar to some growers.

What does low-stress training do?

In nature, marijuana plants typically grow one large stalk, with several smaller ones surrounding it. The main branch receives the most light, eventually producing the healthiest cola at the apex. On the other hand, the lower stems have to make do with the limited resources and light available. As a result, they could only grow undeveloped florets. Such a scenario is highly unfavorable if, like any typical grower, you want prolific yields and massive THC-packed buds.

The solution is simple – low-stress training or LST for short. Essentially, it is all about maximizing energy efficiency to boost growth and yields. It includes having an improved light intake and uniform light distribution across the plant. And to achieve this, you encourage the plants to grow sideways instead of upwards.

Unlike other methods, LST does not entail deliberately damaging the plants. All you need to do is bend and tie them down so they could grow in the desired direction. Later on, you would have a flat canopy instead of the typical structure where one main branch towers over the others. Each stalk can grow like an apex cola composed of dense, hefty buds due to equal light access.

What helps with low stress training?

LST is a reasonably uncomplicated technique with impressive results. But, there are some extra steps you could do to take things to another level. This includes growing the right strain, providing enough light, and topping. When combined – and done correctly – you can expect substantial yields unlike any other.

1. What are the best strains for LST?

One of the best things about low stress training is that it is compatible with both photoperiod seeds and autoflower seeds. Growers usually opt for Indica-leaning varieties. That is because LST could promote budding on their often unproductive side branches.

Keep in mind that some strains may respond better to low stress training than others. Not to mention, some are also naturally high-yielding, such as Grandaddy Purple and Amnesia Purple. You can settle on these cultivars for even better results. But this is not mandatory.

Start with high-quality cannabis seeds obtained from a reputable seed bank. If the plants have inferior genes, no amount of training can force them to produce large yields and top-shelf buds. You would only waste valuable time and effort. If you are on a budget, check out these exclusive deals from Homegrown Cannabis Co.

2. What are the best lights for LST?

Lighting plays a critical role in the success of LST. Generally speaking, more lights mean higher quality and quantity of yields. Still, you have to be extra careful with how much light you give the plants. That is because an excess could lead to light burn and heat stress, which is the last thing you want.

The key is to find the sweet spot that receives just the right light intensity. A lux meter is a gadget designed to do precisely that. All you have to do is measure the light intensity values – expressed in lux – in various spots in the growing area. Here are the light requirements of cannabis plants across the different growth stages.

Growth Stage Ideal Light Intensity
Seedlings 5,000-7,000 lux
Vegetative 15,000-50,000 lux
Flowering 45,000-65,000 lux

When measuring, note which areas are well-lit. Rearrange the plants accordingly. Now, determine the height above the canopy that receives ample lighting. That is your sweet spot. The end goal is for the plants to reach that height.

3. Is LST or topping better?

Topping is a pruning method that involves removing the top section of the central stalk. Doing so stimulates the formation of new branches and bud sites. Incidentally, it also encourages horizontal growth, helping flatten the canopy and maximize light access.

Although topping is not required, doing it as a preliminary step, though, can dramatically improve the results of the procedure. So even if it may slow down growth to a certain extent, the rewards are more than worth it.

Note: Topping, while simple, is still a high-stress training method. You will have to skip this step if you are growing autoflowers. Due to their rapid growth cycle, the plants may not have enough time to bounce back to health in case they get injured.

When should you start low stress training?

LST is typically done in the vegetative stage. During this period, the plants are still young and pliable, which means that they would respond well to training and manipulation. Timing plays a critical role in the success of LST. If the plants are too young, they could get stressed out. On the other hand, if they are too mature, the stems would already be rigid, and they could snap into two when bent.

But really, LST is pretty straightforward to do. It does require patience and dedication. And if you are a beginner, there might be a bit of a learning curve involved, but do not be discouraged. With practice, you would master the skill in no time.

Step 1: Prepare your equipment and supplies

Before anything else, make sure to gather the supplies you would need. You really just require two – the cutting tool and ties.

Scissors. This will be used when topping the plants. The sharper the scissors, the better. It would allow you to make clean, precise cuts, helping reduce the risk of trauma and infection. If possible, opt for these pruning snips from Fiskars. Make sure not to use anything with serrated blades. And, do not forget to sterilize the scissors before getting started.

Ties. You will need twisty ties from the local gardening store to secure the plants into place after bending them. Being flexible and soft, they can easily be fashioned into shapes without wounding the stems. You could also use other tying materials as long as they are not thin and sharp enough to cut through the stalk. For larger plants with sturdier branches, you may need soft wire ties to fasten them down.

Step 2: Topping the plants

Topping is typically done when the marijuana plant is around 10 inches tall and has 4-6 nodes. During this point, the plant would be strong enough to endure the stress, helping it recover faster.

Note: The nodes – also called the growth tips – are the intersection between the branches and the main stem. This is where the buds will later emerge.

Begin by holding the uppermost shoot. Carefully snip off the top growth down to the third note (from the plant base). Do not cut it all the way – make sure to leave a tiny bit of stem. This will help secure the petioles – the small stalk with the leaves – on either side of the stem.

Monitor the plants. Within a few days, the tiny growth tips would come out. Once the plant forms 4-6 more nodes, you can repeat the topping process to grow more branches. Ensure that the plant has fully recovered before doing so.

Step 3: Bending and tying down the plants

After topping, you can proceed to the heart of LST – bending and securing parts of the plant. Remember, you want each stalk to be of the same height. This way, all the buds will receive equal amounts of light. With that in mind, simply bend the taller stems to even out the canopy.

Note: Sift through the plant, making sure to opt for young, flexible stems – usually found near the branch tips. Apply gentle pressure when bending. If you accidentally break a stem, tape it immediately so it can heal itself.

After bending, the next step is to secure the stalk in place with the appropriate tying material. You may need to drill some holes on top of the pot. This is where you will loop and fasten the tie. Another option is to position bamboo stakes on the ground and wrap the tie around them. If you are using fabric pots, all you need to do is pierce some safety pins and coil the ties around them tightly.

Keep an eye on the plants for the next few days. Make sure to immediately bend any stem that is out of position. Keep at it throughout the vegetative stage until you attain the desired height, width, and shape of the plants.

Step 4: Flipping into flower

Towards the end of vegging, your marijuana plants should resemble a table, with the canopy flat and even. Ideally, the plants should also be about half of the preferred height. If this is the case, you can force the plants to start flowering by switching to a 12/12 light schedule.

Within the first few weeks, you can expect the plants to double in size as they start budding. At this point, you can continue with LST to maintain the shape and height of the canopy. Just be extremely careful when doing so. You don’t want to touch the buds, which could damage the resin glands.

Note: While you can resume with LST during the flowering stage, you can’t start the training by then. It would already be too late. Even worse, you could compromise the production of cannabinoids, terpenes, and other valuable compounds. Remember, you can only start with LST while the plants are vegetating.

After a month in the flowering phase, you should be done training the plants. Rest assured that they will preserve their current structure and shape in the next few weeks. But, if some branches become too close to the lamps, feel free to train the plants again.

What if there are no issues, and the plants just keep on budding as desired? Well, pat yourself on the back – you’re almost there. Now comes the waiting game. Sit back and relax, but do check on the plants to ensure they are healthy. During harvest time, you’ll be collecting an abundant yield of massive, dense, and trichome-packed buds.

Why train your plants…

At the very least, even if it is your first time growing marijuana, you should train the plants. LST, for example, is incredibly easy to do. The risk of injury is minimal, and it does not cause too much stress. Should you make a mistake, there is time for the plants to recover without compromising their overall quality and yields.