Whether you want to control plant growth, maximize your yield or ensure an even crop when growing different strains in the same area, pruning is an important tool.
It can help to limit plant size, promote lateral branching and delay the onset of flowering. Pruning also reduces the risk of mold and pest infestations.
Apical Pruning
Apical pruning is one of the most common types of cannabis growing techniques. It is performed by removing the upper part of a plant’s main stem to increase its size and production. The process is very simple: cutting the apex of the main stem paralyzes its growth, boosting the production of side branches (and fatter lower branches) that grow from it.
This pruning method is used by many commercial marijuana growers and is very effective because it can yield up to a kilo of buds per plant in a small space. It also helps to ensure the plants have an even distribution of bud production and can produce better quality buds.
However, apical pruning does have some downsides, so it should be done in moderation. It should be avoided during flowering as it can interrupt hormone production and movement, which is necessary for flower and bud development.
When pruning marijuana, you should always use sharp scissors that have been previously sterilized with alcohol to prevent any unwanted infection from occurring. This will ensure that you get the best results possible from your pruning efforts.
Pruning can also be done at different stages in the growth cycle of a cannabis plant, although it is not advisable to prune more than two weeks into the flowering stage, as this can disrupt the hormonal production and movement that is necessary for flower and bud development. The effects of pruning can vary by the variety being grown and the time frame for which the plant is growing, but most cannabis cultivators agree that apical pruning is a good way to maximize production in cannabis cultivation.
Vertical Pruning
Vertical pruning is an important tool for increasing cannabis yields. It is especially beneficial for growers of Sativas and Sativa/Indica hybrids, which tend to produce vigorous and branchy growth that will recover very quickly after top-tuning or tying down.
When growing taller plants, the distance between the shoot apex and the plant base increases compared to smaller plants, which entails larger hormonal and micro-climate gradients along the plants and lower values at the bottom parts of the plant canopy [31]. Furthermore, increased light penetration down the shoot can increase the efficiency of photosynthesis and induce changes in physiological and chemical properties along the plant, which can also impact cannabis production.
Pruning can also be used to shape the plant and make it more bushy, which can increase the number of buds on each stem and the quality of the buds themselves. Topping is the most common method of HST; however, there is a technique called fimming that works much like topping but can also create up to four new main colas.
It is important to use a sharp pair of scissors when pruning. The blades should be shaped to the desired pruning cut and they should be previously sterilized with alcohol to ensure that cuts are clean and free of infection. Then, always make your pruning cuts flush to the branch and never leave a stub.
Horizontal Pruning
Pruning techniques that alter the plant architecture can impact yield. This includes altering the position of inflorescences and their light intensity inside the canopy. In cannabis, changes in these parameters were shown to influence yield quantity and quality [6,8,9], although the precise effect of pruning on this process remains unclear.
Increasing the proportion of horizontal branches in your plant is a good way to increase fruit production. Upright branches grow lots of vegetative growth but produce little fruit, while vertical shoots produce plenty of buds but their fruits are often soft and poorly colored because they are shaded by the branches above.
Prune horizontal branches every year in late summer to maintain their shape and ensure a uniform height for the plant. This will result in a stronger and healthier plant that can produce more buds at the same time.
Another advantage of using this technique is that it allows for the harvesting of more cuttings from each plant. These cuttings are easier to remove than a single big bud that could fall prey to bud-rot, and they also result in better-quality buds.
In addition to the above-mentioned techniques, a number of other methods are used by growers to improve their plants’ performance and production. Some of these include bending the stem of the plant in order to correct it and promote more branching.
Unlike apical pruning, horizontal pruning is not as common in cultivation systems, but can be effective for large-scale growers who use a lot of vertical space to train their plants to a particular shape or size. For example, in an espalier system you prune back the main central stem in winter to stimulate strong side-shoots that will form additional tiers of branches.
Crushing
Crushing cannabis leaves can have a significant impact on the size and quality of your harvest. However, this is an advanced technique that can be difficult to master, so it is important to know exactly how to perform it correctly.
The effects of crushing are mainly related to the shape and size of the buds that are produced, but it also has a large impact on the overall yield. In general, plants that have been crushed will produce less resin and trichomes than those that have not.
A good rule of thumb is to never crush the fan leaves on a cannabis plant. These leaves hold sugars and food that the buds need to grow. Leaving them uncut can cause them to rot.
For this reason, it is recommended to only prune fan leaves during the flowering stage of a plant’s life cycle. This way, the flowers will be able to receive more light and grow larger and more robust.
Another pruning method that is sometimes used to increase the size and quality of a crop is lollipopping, which means “breaking the plant”. This involves clipping off small branches and limbs found at the bottom of a plant, thus increasing the amount of air that reaches the lower parts.
In addition, removing limbs channels the plant’s nutrients to parts of the plant that receive more light. This can help the buds to grow and fatten faster, leading to a better harvest.
Topping can be done during the vegetative growth phase, but it is best to wait until the plant has developed more than seven nodes. This allows the plant to focus its energy into lateral growth that will produce a bushy, squat-looking canopy.
Defoliation
Defoliation is a common form of pruning that allows plants to absorb more light. It can be a valuable tool to growers who want heavy blooms, but it’s best done carefully and in moderation.
In nature, cannabis plants use their leaves to store nutrients during stressful times such as droughts, nutrient shortages and pest infestations. For indoor growers, however, this excess foliage becomes more of a burden than an asset.
This extra canopy can also cause issues with airflow and reduce a plant’s ability to absorb CO2. It is particularly harmful for lower and inner sections of the plant that don’t have as much oxygen available.
The removal of excess foliage can help to improve airflow around your plants, reducing the risk of mould and other pests as well as improving the quality of your harvest. It can also encourage a better balance between transpiration and photosynthesis, thereby increasing the overall efficiency of your grow space.
Many people use a curved trimming scissors for this purpose, as they allow you to make precise cuts and are great for removing the most leaves at one time without stressing your plant out.
Defoliation can be a valuable tool in boosting your cannabis yields, but it’s important to do it properly and in moderation. Performing it at the wrong time or in a manner that stresses your plant can result in stunted growth, reduced yields and even death.
Whether or not to defoliate depends on a variety of factors, including your region’s weather conditions and the specific strain you are growing. Some strains are able to cope with a moderate amount of defoliation, whilst others are better suited to a less aggressive approach.