LST vs. Topping: Which Training Method Works Best for Autoflowers?

Autoflowering cannabis plants are known for their quick growth cycle and compact size. Unlike photoperiod plants, autoflowers begin flowering based on age rather than light cycles, making them a favorite among growers who want fast and efficient harvests.

To maximize yields, growers often use plant training techniques like low-stress training (LST) and topping. Both methods help control plant height, improve light exposure, and encourage bigger bud production. But which one works best for autoflowers?

This article explores the differences between LST and topping, their benefits, risks, and which method is more suitable for autoflowering strains.

Understanding Low-Stress Training (LST)

What is LST?

Low-stress training (LST) is a gentle technique used to manipulate a plant’s structure without causing significant stress. By bending and securing branches, growers create a more even canopy, allowing more light to reach lower bud sites.

Benefits of LST for Autoflowers

1. Maximizes light exposure – Even light distribution promotes uniform bud development.
2. Reduces plant height – Ideal for small grow spaces or stealth grows.
3. Prevents stress-related growth slowdowns – Since autoflowers have a short vegetative phase, avoiding stress is crucial.
4. Boosts yields – More bud sites receive light, leading to better overall production.

How to Perform LST on Autoflowers

1. Start training when the plant develops at least 3-4 nodes.
2. Gently bend the main stem and side branches away from the center.
3. Secure the branches using soft plant ties or coated wire.
4. Continue adjusting and guiding the plant as it grows.

Since LST does not involve cutting, plants recover quickly, making it a safe option for autoflowers.

Understanding Topping

What is Topping?

Topping is a high-stress training method where the plant’s main stem is cut off at the fifth or sixth node. This technique is particularly beneficial for high-yielding autoflower strains, as it forces the plant to grow multiple main colas instead of a single dominant one.

Benefits of Topping for Autoflowers

1. Encourages multiple colas – This leads to a bushier plant with more bud sites.
2. Improves canopy control – Helps manage height and shape for indoor growing.
3. Distributes growth energy evenly – Instead of focusing energy on one cola, the plant spreads it across multiple branches.

How to Perform Topping on Autoflowers

1. Wait until the plant has at least 4-5 nodes before making the cut.
2. Use sterile scissors to remove the top growth just above the third or fourth node.
3. Allow the plant time to recover and watch for new branch growth.

Topping creates more bud sites, but since autoflowers have limited time to recover, it carries more risk than LST.

LST vs. Topping: Key Differences

Factor LST Topping

Stress Level Low High

Best for Beginners Yes No

Effect on Yield Increases by improving light exposure Increases by creating more colas

Recovery Time Quick Slower

Best Stage for Training Early vegetative phase Before flowering begins

Risk of Stunted Growth Low Higher risk

Which Training Method is Better for Autoflowers?

Why LST is the Preferred Method for Autoflowers

LST is the safest and most effective training method for autoflowers. Since these plants have a short lifecycle, they don’t have much time to recover from high-stress techniques like topping.

By gently bending the branches and maintaining even light exposure, LST helps autoflowers maximize bud production without growth setbacks.

When Topping Might Work

Some experienced growers successfully top autoflowers, but only under the right conditions:

• The strain is known for vigorous growth.
• The plant is healthy and strong.
• The topping is done early, around week 3, before the flowering phase begins.

However, topping an autoflower too late or stressing it too much can lead to reduced yields instead of increasing them.

How to Combine LST and Topping for Autoflowers

For growers who want the best of both worlds, combining LST and topping can be an option. Here’s how:

1. Top the plant at the third or fourth node while it is still in the early vegetative stage.
2. Once new growth develops, apply LST by bending the side branches outward.
3. Continue adjusting the branches as the plant grows to maintain an even canopy.

This method requires careful timing and is best suited for fast-growing strains.

Common Mistakes to Avoid

1. Topping too late – Autoflowers transition to flowering quickly, so topping beyond week 3 can stunt growth.
2. Using too much force in LST – Bending branches too aggressively can cause them to snap.
3. Ignoring plant health – Only apply training methods to strong, healthy plants.
4. Not adjusting LST as the plant grows – Regular adjustments ensure all bud sites get adequate light.

Conclusion

LST and topping are both effective training techniques, but for autoflowers, LST is the safer and more reliable choice. It helps improve light exposure, increases yields, and keeps plants manageable without causing excessive stress.

Topping can work in some cases, but it carries more risk due to the plant’s short lifecycle. Growers should only attempt topping if they have experience and are working with a strong, fast-growing strain.

For best results, beginners should stick with LST alone, while advanced growers may experiment with a combination of both techniques. Understanding the growth pattern of your autoflowers is key to making the right training decision.