Low Stress Training: How to start LST on weed plants?

One of the best things about growing your own weed is having to experiment with your plants and see if you can in any way affect their behavior. Most growers are interested in increasing their yields by making their flowers bigger and thicker. This is done by maintaining an optimal growing environment, feeding your plants the right nutrients - and of course, training them. Low stress training is a great training technique that can do wonders for your plants.

High stress and low stress training techniques have been used for a while now, and not only with cannabis. There are other training techniques out there as well, such as the famous Japanese bonsai trees which are grown as miniature copies of otherwise normal trees.

This guide on low stress training will show you how to train your plants with just a roll of twine and some creativity. You’ll also learn when to start LST on weed plants, what is the best material for LST, and lots more!

Before we get to the guide - let’s cover one of the most commonly asked questions: what is LST?

What is LST?

LST is short for low stress training. It is a plant training technique which includes tying branches down to create a wider canopy and make the most of your growing space and lighting.

Managing your branches will allow for a more even, almost flat canopy which will have a much better light distribution than a plant would normally without LST.

This will allow for more vegetation, and ultimately bigger yields since your “popcorn” buds will grow bigger without taking anything away from the buds on main colas.

LST can be done with photoperiodic and autoflowering plants, as well as both indoor and outdoors. However, it is most commonly performed indoors, where plants grow in a more controlled environment.

It is commonly applied in other growing techniques such as SCROG to absorb as much PAR light as possible, where a net is introduced into the grow setup.

scrog net

Which materials are best for LST?

When tying down your plants it's important to keep in mind that you don't want to harm the branches. Certain materials will do that - such as fishing line. Fishing line, sewing thread and similar sharp materials can lacerate your plants which could have an adverse effect on your plant and cause that branch to underperform.

It is best to use materials such as gardening twine or hemp rope, either will do great. They’re thicker, easier to use, and definitely won’t hurt your plants.

Low stress training - step by step guide

If you’re looking to learn how to perform low stress training on your plants, look no further. We’ve prepared a short step-by-step low stress training guide that will have you tying down plants in no time!

What you’ll need:

  • Fabric or plastic pot
  • Nail, screwdriver or something sharp to punch holes in fabric pots
  • You can use a hand drill for plastic pots
  • Plastic or stainless steel anchor stakes (optional)
  • Garden ties or hemp twine

Step 1 - Prepare the pots

If you plan on using fabric pots, you can punch a hole near the top of the pot with a nail, a screwdriver, or a knife. These won’t help with plastic pots, in which case you’ll have to use a small drill to make ¼ inch (~1cm) holes on the side of your pot.

You’ll probably want to make 6-8 holes on your pots in order to have enough places to tie your ties once you start doing low stress training.

Step 2 - Plant your seedlings

Once you’ve gotten the pots ready, you can move in your plants. Nothing unusual - one plant per pot. The only thing different you might want to do is to plant it closer to the edge, rather than in the middle of the pot.

Step 3 - Tying down for the 1st time

Now that you’ve moved the plants in their new homes, they will soon be ready to start LST. But first, you must give them some 2-3 days to spread their roots in the new pots. Tying down your plants too early can cause them to fall over,

Most growers recommend that you let the plant grow about 5 nodes (pairs of leaves) in height before doing LST. Once the 5th node appears, you can tie down the top of the plant to the hole on the opposite side of the pot.

You will notice the plant will start having new vegetative growth on the sides of the stalk which will tend to grow upwards (towards the light) and soon enough you’ll be able to tie down those branches as well!

lst on autoflower
Source: amsterdamgenetics.com

Step 4 - Combine techniques (optional)

Keep in mind that you can combine other training techniques with LST. If your plants are photoperiodic, you can do some topping.

However, if you’re growing autoflowering plants you might want to consider some other, less aggressive technique such as defoliating or lollipopping. Combining this technique with SCROG might be a really good call, but we’ll get into that a bit later...

While we’re on the topic of autoflowering plants, let’s check out how to do LST on autoflowers and why other training techniques may not be the best choice in the long run.

LST on autoflowering plants

Since autoflowering plants have a predetermined life cycle, compared to photoperiodic plants which can stay in the vegetative phase for as long as you don't flip them, there aren’t too many training techniques that can be applied on them.

High stress training techniques such as topping, fimming and alike are risky as they might significantly reduce your potential yields if you top too late and the plant doesn’t have time to recover. This is why LST on autoflowering plants is one of the most efficient training techniques when applied correctly of course.

Many growers like to apply LST on autoflowering plants and then combine that with a SCROG net to get the best light distribution or some other growing technique that would help the plant’s limited buds to grow thicker.

When should you start low stress training?

The simple answer is - whenever you think the plant is ready for it. Try bending it gently left and right for a bit to see how soft the stalk is. You have to start before the stalk starts turning brown, otherwise, it might snap. But also try to avoid starting too soon as your plants might not react too well.

We’d recommend waiting for at least 4-5 nodes to grow out before doing any training techniques. You can even top the plant once in these early stages and then tie it down. This should cause it to grow significant vegetation on the sides, which will later turn into big colas full of big buds.

How much does LST increase yield?

The amount of cannabis you get by applying LST methods isn’t easily measurable - but the math behind the reasoning is clear. By getting more light to your main and side colas, as well as lower branches, you increase the size and thickness of your buds.

In order to compare the amounts between a trained, and non-trained plant you’d have to grow them and compare the yields after drying and trimming your plants - which we definitely encourage you to do!

Should I remove fan leaves during flowering?

Yes, however, make sure you don’t remove them too early. Leaves are very important for photosynthesis and lots of different other processes going on in the plant, and removing them too early will harm your plant.

Removing fan leaves is called defoliation, and it can increase your yields if done right, and decrease if done wrong.

You should wait until a week after your plants go into flowering, and then remove 20-30% of the leaves in the mid and upper parts of the canopy every 5-7 days. This way you’ll see how your plants react, without overdoing it and hurting them in the process.

How late into flower can you do LST?

There’s really no time limit on how late you can start with LST. You can basically start in week 2, week 3, or any other week except for the first. You can do LST all the way through to harvesting the plants because you want as many colas getting as much light as possible.

How do you LST after topping?

As we mentioned before, if you’re going to top autoflowering plants - top them relatively soon in their life, so they can recover and grow several colas after the topping.

After you top the plants, let them recover for 2-3 days, and then tie them down using soft garden ties and stakes, or twine - however, soft garden ties might be a tad better for the early stages. You can start using twine and/or rope when your side branches start getting stronger.