Come potare una pianta di cannabis - terredicannabis

How to prune a cannabis plant

The art of pruning is a discipline very dear to growers, both for those who grow professionally and for those who dedicate themselves to balcony gardening.

Why is pruning so important? Plants often tend to produce many branches and leaves, so many that they strain the entire main structure , with a consequent slowdown in growth. Eliminating superfluous parts is the best way to induce the cannabis plant to take on a pre-established shape, depending on the grower's needs, or more generally to ensure that the plant concentrates all its energy on the largest buds , without dissipating them to grow flowers that will never reach appreciable size.

There are many cannabis pruning techniques, differing in difficulty and objectives. They all have one thing in common: concentrating the plant's energy towards the main buds, which are larger and more exposed to light, with the aim of maximizing yield in terms of harvest.

What are the main cannabis pruning techniques? 


Defoliation is a form of pruning and involves removing leaves from cannabis plants, to concentrate resin production in the larger buds and improve yield at harvest. With defoliation the grower can manipulate the growth of the plant: the more nodes will receive direct light and the more flowers will develop, with greater quantities of resin. The increased airflow through the entire plant structure will also help prevent pathogen attack and promote efficient gas exchange by the stomata.

The Topping

Trimming, also known as topping, is a pruning technique that consists of cutting the tip of the main stem of a cannabis plant. Techniques of this type are called HST - High Stress Training, since they cause strong stress to the plant. If not treated with special pruning, the marijuana plant tends to take on the typical conical shape similar to that of a Christmas tree , characterized by a large central bud and more or less developed lateral branches.

Removing the apical bud will give rise to two new buds , stimulating the plant to develop secondary branches. The objective is to prevent the plants from taking on the famous Christmas tree shape, to allow the light to irradiate the entire plant and the nutrients to spread as best as possible.


Main-lining – also called Fluxing – is a cannabis pruning technique that has become very famous in recent years. As with the other techniques mentioned, the final goal is to shape the plants to optimize growth spaces and obtain more abundant harvests.

Main-lining is based on a rather ingenious principle, which involves shaping the seedlings by forcing them to develop a main stem in a shape similar to that of an engine manifold , similar to a Y-shaped structure. The process must be repeated on all the new ramifications born during the vegetative phase. If done well, this technique allows you to create multiple apical buds, which can be doubled as many times as you want.


Schwazzing is a pruning technique that consists of very aggressive defoliation . It involves removing a large number of large leaves from a plant, in order to expose as much of its surface area to light as possible.

Schwazzing should be performed twice in a plant's growth cycle. The first occurs shortly before the start of the flowering phase . Schwazzing is repeated about a third of the way through the flowering phase , approximately 20 days after the first run.


FIM pruning

FIM pruning consists of making a small cut at the apical tip of the plant to obtain the multiplication of the auxiliary branches, with the aim of having up to 5-7 small apical tips .

With this method, a greater result can be obtained since all the main tips of the plant are at the same height and the light intensity received is distributed uniformly in all areas of the plant. It is important to know the inverse square law to know how light reflects off objects based on their distance, and how it affects cannabis plants. This technique is better suited to plants grown from seeds than from cuttings selected from a mother plant, because they have a higher biological age and the production of mother cells is very low, consequently, the chances of success with this technique are drastically reduced.

LST (Low Stress Training) technique

There are several techniques designed to modify the vegetative structure of cannabis , without causing severe stress to the plant. These are minimally invasive techniques - also known by the acronym LST (Low Stress Training) - which induce the plant to grow horizontally , by tying the branches with wires or ropes. These are tensioned downwards, thus obtaining a more uniform growth of all the branches and internal parts of the plant.

In the most used LST technique it is necessary to grow the plant up to the 4th-5th node, after which the apical tip will be cut. Once cut, the stem can be tied with a rope attached to the edge of the vase or to a weight placed on the ground. As the plant grows, it will be necessary to re-tension, achieving the growth of the branches at the same height.

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