BackLow Stress Training (LST) for Cannabis: Complete Grow Guide

The LST technique (Low Stress Training) is one of the most effective and gentle methods to optimize cannabis cultivation. Unlike high-stress techniques such as topping, heavy pruning, or supercropping, LST does not damage the plant but carefully guides its growth. The result: compact plants, even bud development, and higher yields. Originally used in vineyards and orchards, LST has become a must for both indoor grow tents and outdoor cannabis gardens.

What is Low Stress Training (LST)?

LST stands for “Low Stress Training.” It involves bending and guiding stems horizontally instead of letting them grow vertically and naturally. This creates a wider, bushier structure with multiple tops at the same height. These tops receive light evenly, improving photosynthesis and stimulating more balanced bud production.

The science behind it is called phototropism—plants naturally orient themselves towards light. When a main stem is bent down, shaded areas produce more growth hormones (auxins), activating side shoots. The result: more vigorous branches and more flower sites.

Why use LST in your cannabis grow?

• Higher yields: Instead of one large central cola, LST produces several equally strong tops that mature at the same time.
• Compact plants: Essential for indoor grows, where space is limited and plants must not reach the lights or windows.
• Lower risk of mold: An open structure with better airflow helps prevent botrytis and powdery mildew.
• Versatile technique: Works in indoor grow tents and outdoor grows, with soil, coco, or hydroponics.
• Perfect for autoflower strains: Since autos have little recovery time, LST is the best training method to boost yields without slowing growth.

When to start LST?

The best time to start is during the vegetative stage, once the plant has developed 4–6 nodes. At this point, stems are flexible and easy to bend. LST can also be applied during the early weeks of flowering (the stretch phase), though stems become stiffer and more fragile later on.

Essential tools for LST

• Soft garden ties or coated training wire.
• Thin but strong string.
• Plastic plant clips or hooks.
• Optional SCROG net for structured training.
• Wooden stakes for extra support.
• Plant tape to repair small splits.

LST step-by-step tutorial

1. Bend the main stem

Start by gently bending the main stem to the side and securing it to the rim of the pot. This breaks apical dominance and encourages side branches to grow stronger.

2. Train the side branches

As side shoots grow, bend them horizontally as well and spread them out like a fan. The goal is a flat, even canopy.

3. Make regular adjustments

Cannabis grows quickly, so check your ties every few days. Loosen or extend them to prevent stems from being strangled.

4. Maintain during flowering

During the stretch phase, adjust branches to maintain an even height. After week 3–4 of flowering, it’s best to stop bending and let the plant focus on bud development.

Advanced LST variations

• With SCROG nets: Perfect for indoor grows. Each branch is guided through the net holes, maximizing light efficiency.
• With weights: Small, lightweight objects are hung on branches to bend them gently. Popular outdoors, as branches can still move with the wind.
• Spiral training: Guide the plant around the pot in a circle to maximize space.
• Gentle supercropping: For advanced growers only—slightly “crimp” stems to make them bendable without breaking.

LST indoors vs. outdoors

In indoor grow tents, LST is vital for controlling plant height and optimizing lamp distance. A flat canopy ensures even PPFD distribution and prevents light burn.

In outdoor grows, LST helps keep plants discreet and more resistant to wind and humidity. It also lowers the risk of mold after rain by improving natural airflow.

LST in coco and hydroponics

In coco and hydro systems, where plants grow faster, LST is especially effective. A wider canopy means more light use and nutrient absorption, leading to denser buds. Adjust watering and nutrient solution to match the increased leaf mass.

LST for autoflower strains

Autoflower strains go from seed to harvest in just a few weeks. High-stress methods can slow them down, but LST is perfect to boost their potential without stunting growth. Modern autoflowers respond very well, as long as training starts early and gently.

Common LST mistakes

• Starting too late, when stems are already stiff.
• Bending too sharply, causing breaks.
• Using ties that cut into stems.
• Not checking and adjusting ties regularly.
• Allowing one top to grow taller than the rest, breaking canopy uniformity.
• Making too many adjustments at once instead of gradual training.

Yields, quality & terpenes

A flat, even canopy increases light efficiency and lets light penetrate deeper. This leads to bigger, more uniform buds, fewer popcorn flowers, and better airflow. Reduced moisture stress also boosts resin and terpene production, improving overall quality.

Practical checklist before flowering

• The canopy is even, with no dominant tops.
• No ties are cutting into stems.
• Good airflow under and through the canopy.
• Watering and nutrients adjusted for increased foliage.
• Final gentle adjustments made early in the stretch, then let buds bulk up.

Legal disclaimer

Always check the laws in your country or region. This article is for educational purposes only. Grow cannabis only where it is legally permitted.

FAQ – Frequently asked questions about LST

Is LST suitable for beginners?

Yes. With patience and gentle movements, anyone can apply LST successfully.

How often should I adjust ties?

Every 2–4 days during veg. During the stretch, even daily. In late flowering, avoid further adjustments.

Can I combine LST with SCROG?

Absolutely. LST positions the branches, and the SCROG net maintains an even canopy for maximum efficiency.

Does LST work for both indica and sativa?

Yes. Indicas become wider, while sativas are kept under control in height. Both benefit from training.

What if a branch breaks?

Support it and tape the break. If not fully snapped, it usually recovers quickly.

Until when should I do LST?

Up until the early weeks of flowering. After that, let the plant focus on bud and resin production.