Lesson #5A: How to Low-Stress-Train (LST) Your Plants: Autoflowers or Photoperiods
by Henrique Dias on Mar 11, 2021
Everything taught and sold by BudTrainer is to be used strictly for legal purposes. We absolutely condemn the production of illegal substances, and it is your duty to ensure that you are complying with the law. The words "hemp", "cannabis", "weed", and "marijuana" are used interchangeably to refer to the same plant (legal hemp with less than 0.3% THC) for the purposes of this lesson.
Low-Stress Trained (LST) cannabis plant during week 8 of flower
Experience level: Beginner
When to start: In final pot, after 5th node
Space needed: 2' by 2' per plant, or 3' by 3' if you want to push it
Low-Stress-Training Clones: highly recommended
Low-Stress-Training Autoflowers: highly recommended
What you need:
- Soft garden ties
- Pruning shears or thin tip scissors
- Hole punch or a pointy knife (or use a training pot)
- Anchor stakes for tying your seedling down (can use garden ties too)
- Please note: our old BudStakes shown throughout this guide have been discontinued but you can use any wire or stake instead.
- LST clips for training your plant at later stages (optional)
- Grafting tape or duct tape (in case of accidents)
Advantages of Low-Stress-Training cannabis plants:
- Larger yields compared to an untrained plant
- Fatter top colas and less popcorn bud
- More airflow through the canopy and fewer pests
- Creates lower profile and more bushy plants
- The easiest cannabis training technique
Disadvantages of Low-Stress-Training cannabis plants:
- NONE. Low-Stress-Training is single-handedly the safest, fastest, and highest yielding cannabis training method.
So what defines Low-Stress Training, really?
In general, low-stress training is any kind of cannabis training technique that involves bending your branches in different directions in order to increase your canopy space, the amount of light your plant receives, and ultimately, increase your yields. Unlike High-Stress Training, LST doesn’t involve cracking your branches or cutting parts off your cannabis plant. Instead, LST is meant to be gentle and you are not supposed to break plant tissue when doing it.
Cannabis seedling 1 week after Low-Stress-Training
How many versions of LST are there?
LST isn’t one specific technique, but a range of them. Some people like to grow their plants in a spiral shape; others prefer to pull their side branches down in a Christmas tree shape; and some, like us, prefer to train their plants sideways. Another kind of LST, which is quite an advanced technique, is a ScrOG, or Screen of Green, where you use a net to evenly distribute your colas. The point of all of them is to grow your plant horizontally instead of vertically so that it gets more light and you end up with not only a higher yield but also more and bigger top colas (with none of that popcorn bud shit).
Why is LST such a popular cannabis training technique?
- It’s almost impossible to fuck up LST, which means anyone can do it.
- LST yields are usually the highest among any other training technique.
- LST only stunts your immediate growth by a few hours, while High-Stress Training (HST) can stunt immediate growth for up to a few days.
- If you are growing auto-flowers, LST is the only option you should use because autoflowers don’t have enough time to recover from high stresses.
LST cannabis plant after 2 months of growth
BEFORE GETTING STARTED
BudTrainer tip #1: do not use thin strings or wires to tie your plants since they will cut through the epidermis (the outer skin), which will limit the ability of your plants to transport sugars and thus to grow. Instead, use rubber-covered ties that are soft and won’t hurt your plants, like the extra thin and soft
Thin wire garden ties VS rubber-covered garden ties
BudTrainer tip #2: if you break any branches while doing this, don’t worry - we’ve broken countless branches in the past, and we assure you that your plants will recover in no time. Just keep some grafting tape or duct tape with you in case you have to glue a branch back together. It works 90% of the time and is as simple as the diagram below (you don't even need the pencil - just tape will do).
Image by Gardening Know How
BudTrainer tip #3: when choosing which branches you want to train, make sure that you pick the stems that are still soft and bendy. If they appear hard and woody they are likely to crack, and sometimes you will not be able to recover from that damage
Soft tissue versus woody tissue: always choose soft tissue to train
LST: THE PROCESS
The stalk from an LST can be twice as thick as a non-trained plant
Step 1 - Preparing the pots
When: Right away
NOTE: fabric pots are better for your plants (and the environment!) since they allow the sides of the media to breathe, which in turn prevents root circling. With fabric pots, the roots of your plant are always growing from the inside out, which makes them much stronger and ultimately allows your plant to yield more bud.
Before you even plant your seed or transplant your seedling, punch holes around the edges of your final pot. We like to punch 8 holes per pot in a pizza-like fashion so that they are well-distributed. Use your hole punch or knife for this. Alternatively, use a training pot that already comes with holes.
Regular pot with punched holes vs training pot with reinforced pots
BudTrainer tip #4: We recommend that you don’t transplant/plant your seedling in the centre of your pot. Instead, transplant it two inches away from the edge (between the two handles, if you are using a fabric pot). This will allow you to grow a larger and longer main stalk. But if you have already planted in the centre, don’t worry - you can still go to Step 1.
Cannabis seedling planted on the edge of the fabric training pot
Step 2 - Tying the seedling down for the first time
When: After your seedling has started showing the 5th node (each node is a pair of opposite leaves + growth sites). In the picture below, the 5th node is just starting to come out.
Cannabis plant with 5 nodes
1. Decide in which direction you will train your cannabis seedling. If you have anchor stakes, insert one anchor 1 inch behind the seedling, and another 1 inch in front of the seedling, toward the direction you want it to grow. Make sure to insert the anchor stakes in the ground at a 45-degree angle instead of straight down so that they don’t come out as the plant grows.
* If you don’t have anchor stakes, use the holes in your pots or stick garden ties in the ground with a U hook at the end (so the roots can grow around it).
Low-Stress Training a cannabis seedling for the first time
2. Cut a 3 inch garden tie and tie it to the anchor stake behind the seedling.
3. Tie the other end of the garden tie to the base of the stalk, pulling it up slightly, like in the picture below.
4. Secure another piece of 3" garden tie to the anchor stake in front of the seedling.
5. Tie the other end of the garden tie between the 3rd and 4th nodes of the seedling, and pull it down until it is roughly sideways, like in the picture below.
Step 3 - Continue tying the seedling down as it grows
When: From when the seedling has grown another 3 to 4 inches long, until it has grown long enough to reach the other end of the pot (roughly 4 weeks).
Insert another anchor stake 2 to 3 inches away from the last one, and tie the top of the plant down again. Repeat this step every 7 to 10 days as the plant grows and reaches the other side of the pot.
During this process, which usually takes a month in total, your side branches will start to grow tall. You can use the sides of your pot in order to tie them down and keep the entire plant on a low profile. Here is a video showing the progress of an LST over 4 weeks (trained it 4 times in total):
Low-Stress Training a cannabis plant over 4 weeks
Step 4 - Topping (optional), defoliating, & flowering
When: once the plant has started growing beyond the sides of the pot.
Cannabis LST that started growing out of the sides of the pot
Topping (optional, mostly for outdoors): if it's still before the last week of July (when cannabis flips to flower) and your plant has already grown past the edges of your pot, you can choose to top your LST in order to "bush it out" even more. Technically speaking, topping is a high-stress technique, however, when the plant it as big as this one, it hardly feels anything. At the time we grew this plant, it was still July - meaning it had one more month of growth, so we definitely topped it! See video below.
Defoliating (outdoors or indoors): at this stage, we also recommend "cleaning up" the middle of your plant and removing all of those leaves that are at the bottom of the canopy and not catching as much sunlight. This is also an important step in preparation for the flowering stage, once the canopy really fills up. Also see video below.
Since this plant above is an outdoors LST, we are going to go ahead and top it multiple times, as well as prune all of the middle leaves that are blocking sunlight from hitting the newer growth sites.
Topping & Defoliating an LST cannabis plant
Just as important during defoliation, is to prune all small growth sites that are non-dominant - like this little shoot in the photo below. Non-dominant shoots never grow to their fullest, and they only take away from their stronger pair. This is why, whenever we see one shoot much smaller than the other, we remove it!
Node with one small growth site and one large growth site
Flipping to flower (indoors only): while we always like to prune our plants back a little bit, it's totally fine if you want to leave your plant untouched, and instead just flip it to flower right away. In fact, if you are growing an autoflower, it will likely be flowering by now already (and you shouldn't prune your autoflowers too much, anyways).
BudTrainer tip #5: We personally don’t like to defoliate like crazy, but we understand that some people do. When in doubt, just remember that you can always cut another leaf or branch, but you can never put them back. However, if you are having pest issues, then it is important to remove all affected leaves in order to help reduce the spread.
Step 5 - Start using your LST clips (optional)
When: once the plant has started growing beyond the sides of the pot (again), all the way until week 2 of flower.
Once your plant is growing far from the edges of your pot, it becomes harder and harder to tie it down. That's why LST clips come in handy at this stage. So go to town on bending those branches while you can, all the way until you hit the second week of flower, at which stage the plant starts slowing down its stretch phase.
For best results, make sure to choose branches that are pointing upward and that still feel soft. If the stem feels woody, it is too late for Low-Stress-Training.
P.S. You can use as many LST clips per branch as you would like!
Attaching Low-Stress Training Clips on a cannabis LST plant
That’s it, folks! This concludes your low-stress training journey and it’s time to reap the fruits (some fine-ass awesome buds) of your labor.
As always, happy growing!
P.S. we prefer to hang dry, and then trim only after it’s been dried so that more cannabinoids and terpenes stay trapped inside. In total, we dry at 60% relative humidity for 7 days, and then we cure everything in glass jars for another 21 days (burping it daily).
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