Many growing techniques have been applied to cannabis plants in order to improve yield and overall quality of inflorescences. High stress training (HST) techniques involve the manipulation of the plant with some radical changes such as cutting, wounding or crushing branches and part of the plant to cause temporary stress and improve the cannabinoid production or the amount of buds.
Well known HST techniques among some growers are:
- Topping;
- Fimming;
- Super cropping;
- Monster cropping.
Let’s start from the basics and go step-by step-through the process.
What is high-stress training in cannabis?
This growing approach is used to increase yields by manipulating the shape of the plant.
By intentionally stressing the plant and physically removing branches or certain parts of it, it is possible to force the plant to create new flowering sites and to promote the development of a bushier, more compact structure.
In this way the plant is capable of supporting heavier buds. The stress caused by HST interventions can stimulate the plant’s natural defense mechanisms, leading to increased production of secondary metabolites. The two of them primarily:
- Cannabidiol (CBD);
- And tetrahydrocannabinol (THC).
Nevertheless not all the cannabis strains are capable of responding successfully to HST, so particular care should be taken by the grower before opting for these techniques.
Considering the growing conditions, stage of growth, availability of nutrients and the particular cannabis cultivar the grower can opt for HST or decide to choose low-stress training (LST), less drastic than HST and with higher chances of success.
Now, let’s take a closer look at all the techniques.
Topping
It involves the cutting of the final part of the apical, the main stem of the cannabis plant, just above an internode. This procedure is performed during the vegetative stage and encourages the growth of a bushier plant and the potential formation of two apicals at the cutting site.
Because of cutting the main stem the plant’s growth hormones will be redirected to lower branches and, if the procedure is performed correctly and at the right time, the overall plant yield will be higher.
Topping can be performed in combination with LST techniques such as Screen of Green (SCROG), to induce the plant growing horizontally instead of vertically, allowing a better light distribution and in turn higher inflorescence formation.
Fimming Your Cannabis Plant
Similar to topping technique, fimming involves the cutting of a smaller portion of the main plant stem. In particular the grower will cut the 80% of the new growth at the top of the apical, just above the node.
This procedure, even if it may look scary at first (scary because it seems like you are deliberately ruining your plant) will potentially lead to the formation of four apicals instead of one and it will promote the growth of a bushier plant with more flowering sites.
Fimming can be stressful for the plant and the growth may temporarily slow down. You have to be careful!
It’s important to perform this HST technique when the plant is ready to face it: the root system should be capable of supporting the stress, so it is recommended to perform the fimming when the plant has from four to six internodes. Nevertheless the success of fimming is strongly dependent on the cannabis cultivar and the individual plant’s response to the stress.
Super cropping
This HST technique consists in bending or intentionally squeezing the cannabis stems, creating small injuries with the main purpose of promoting a powerful growth and larger yields.
The stems are generally compressed at the base of the plant or at the top of the branches, triggering the natural plant’s defense mechanism which stimulates the growth of lateral branches or new nodes.
Super cropping is safer than others because it doesn’t involve the cutting of parts of the plant. Still, it’s better to perform the super cropping when the plant has at least four to six nodes during the vegetative stage.
With an adequate root system the plant can respond better to these intentional stems damaging and recover from the stress before entering the flowering stage. If this technique is performed too late during the growth cycle, it can lead to reduced yields, low quality of inflorescences and low plant development.
Monster cropping
During the flowering stage, in particular around the third or fourth week of flowering, it is possible to take cuttings from the plant and transplant them into new pots.
The cuttings will exhibit peculiar growth patterns, such as bigger than normal leaves and a bushier plant shape.
Cuttings for monster cropping come from the bottom part of a flowering plant, which is richer in hormones and nutrients. Cuttings for normal cloning come from the top of a non-flowering plant.
Monster Cropping can be a complex and time-consuming technique, because it requires extra care for successful growth of new cuttings. Since the cuttings are taken from a flowering plant, extra-time could be required for the new plants to return to the vegetative stage.
HST vs LST? All HST pros and cons
The goal of both techniques is to improve yields, increase the inflorescence size and promote more even foliage growth.
Here’s a list of pros and cons of HST techniques compared to LST methods.
Pros of HST:
- Can be used to create more complex canopy shapes;
- Can result in faster and greater results compared to LST;
- The manipulation of the plant structure can be more precise and targeted;
- May be more effective for certain strains and growth patterns.
Cons of HST:
- Can result in lower yields compared to LST, if not performed correctly;
- May require more maintenance compared to LST;
- Requires more skill and experience to perform correctly;
- Can be more stressful for the plant and may require longer recovery time;
- Could lead to plant death if not performed accurately.
The Wrap Up?
Both LST and HST methods have their own unique advantages. It is up to the grower to choose the preferred growing style. You should consider the cannabis plant strain, the growing stage and the cultivation conditions.
With HST, however, it’s recommended to be extremely careful: don’t ruin the plant while chasing a higher yield. Keep high stress training just as much “high stress” as the plants can take.
