Growing plants comes with a major learning curve, which means the more patient, curious, and consistent the grower is, the better the results will be. And when it comes to curious patience and consistency, low-stress training (LST) is one of the best approaches for allowing plants to thrive.
Similar to bonsai techniques, LST is a plant training method that involves bending and/or tying your plants’ stems with growing tape or duct tape to gently guide or redirect their shape. This ultimately allows plant growers to expose different parts of the plant to air and light, resulting in a higher yield overall when done properly.
What is Low-Stress Training (LST) on cannabis?
So—how does low-stress training tie into cannabis plants?
Cannabis cultivators will opt for this training technique for the exact same reason any other type of plant grower does: to increase yield, which is essential for the still-expanding, ever-demanding national market where margins can be razor thin.
Of course, LST applies to each type of plant somewhat differently, depending on the structure. For cannabis, one large main stem will develop first, eventually creating an elongated cola, which coexists alongside your eventual side branches where your plant’s buds sites will live.
Apical dominance is prominent in cannabis plants, which is defined as the tendency of a plant to grow in a Christmas tree-like shape with thinner sections toward the top. This growth shape will occur naturally, blocking sunlight from reaching the entire plant with a counterproductive effect on growth and yield.
LST is an effective solution to this apical dominance dilemma by opening areas of the plant up to the sunlight and grow lights to ensure light it’s evenly distributed throughout the growth cycle.
It’s largely utilized in mother rooms for propagation purposes, which is when The Flower Shop’s cultivation team usually turns to low-stress training.
“LST really maximizes the clone count in your mother room. You can top the plant to where you’re focused in on a more uniform canopy. We use it in our mother rooms to maximize our cuts. Lots of people utilize low-stress training in the vegetative or pre-flower stages, focusing on that bud production,” said Brandon Alonzo, director of cultivation at The Flower Shop.
How does low-stress training affect cannabis plants?
Unlike high-stress training—which may not give your plant enough time to recover from the process and result in growth damage—LST cannabis is simple, low-budget, and poses little to no threat to your plant’s stems and branches. This method is mainly utilized to increase yield rather than manipulate terpene or cannabinoid profiles.
“LST is done to maximize yield, quality, and space utilization. It is common in all forms of cultivation, indoor, greenhouse, and outdoor growing, and it’s typically done during the early stages of vegetative growth rather than the flowering stage,” said Jesce Horton, CEO at LOWD.
“This method will increase the number of growth nodes at the top of the plant, and also delay vertical growth. Bending will also help the branches to grow in a way that allows each branch to get more light and fill the canopy space. The nodes on the branches benefit by having more light and airflow, the same reasons to properly trim fan leaves. When you have more branches at even height, it creates an even canopy that fully utilizes the lighting efficiency zone and reduces the amount of maintenance work for gardeners.”
How to LST your cannabis plants
There are a few things to keep in mind if you want your plants to grow to their fullest potential utilizing this method over others, like the screen of green (SCROG) or simple natural apical dominance.
Preparing the required equipment for LST training
Traditional low-stress training requires you to utilize tools that allow for bending stems and/or tying them together, but in general, it’s a pretty simple method to prepare for when it comes to equipment.
“You can use garden tape, twist ties, sticks, or netting—anything that allows you to bend a branch in a certain way that helps you manipulate the growth of your plants,” said Christian Pantoja, head cultivation technician at Purple Lotus.
The type of equipment you can utilize is flexible depending on your needs and desires, but as long as you’re working with tools that maximize yield, you can’t go wrong.
“LST has become a standard operating procedure for anyone who is growing at a commercial scale, or even for anyone who is growing at home and not necessarily looking to have the greatest yield. It’s used to manipulate branches so the lower branches and nodes are getting lots of light, increasing yield, and maximizing the canopy space you have to get the most out of your plant, so whatever tools you can use for those benefits, the better,” said Pantoja.
Preparing your room for LST
LST is typically utilized within indoor grow spaces, as these are the areas where things like temperature and humidity circulation are most challenging for growers to maintain.
The main thing you’ll want to focus on when it comes to preparation is your plants’ containers, which are your sources for tying down stems and branches. You’ll want to drill several holes around the rim of your growing container, allowing you to loop ties and twists through the holes to secure your weed plant in the direction you’d like it to grow.
Maintaining your LST throughout the grow
As for long-term maintenance when using low-stress training, there are a few things to keep an eye on for consistent and maximum results.
First, focus on maintaining a flat canopy, ensuring no branch is taller than any of your others. Aim for shaping outward and as far away from the main stem as possible.
Pay close attention to your plant’s directional growth as often as you can, as this isn’t something you’ll be able to forget about a week after you start LST. Consistency is key for most cannabis growth tactics, and low-stress training is no exception.