What Causes Stress In A Cannabis Plant?

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Categories : Cannabis cultivation

What Causes Stress In A Cannabis Plant?

There are many causes of stress in a cannabis plant, some of which may seriously affect the plant health and some which might prove beneficial.

Biological stress is an organism's reaction to stressors (such as environmental conditions) or, in different words, the body's method of responding to a challenge. As all living organisms, the marijuana plant can experience stress and be affected by it. Stress can be abiotic (the impact of non-living factors such as heat, etc.) and biotic (living factors), and it can be beneficial and detrimental to the normal functioning and well-being of the organism.

Most of the time people talk about the stress they mean stress that has a negative impact on an organism, ignoring the fact that there are types of stress that can have a positive effect.

Cannabis stress is mostly caused by imbalances in the chemistry, which starts affecting the normal functioning of the plant. Homeostasis is a concept in biology, which is central to the idea of stress. Homeostasis is an equilibrium in biochemical processes, and a homeostatic point would be an organism's optimal living condition. That means that we can see the stress as factors, which cause an organism to diverge from that equilibrium or its normal functioning.

In conclusion, cannabis, as most living organisms, likes to have a consistent environment. It would be wise for a grower to know the causes of stress and how to deal with them, so the plant can grow healthy, in a state of homeostasis.


The main problem concerning water in cannabis plants is over-watering and under-watering. The cannabis plant needs a specific amount of water to grow well, which depends on different factors, such as the plant's stage of development and growing environment.

Over-watering is one of the most common growing problems for inexperienced growers and root rot is a difficult problem to solve. Insufficient amount of water also causes stress. The plant will wilt, dry out and die, but the solution for that is easy, as you only need to water the dehydrated soil. Symptoms of these types of stress are wilting and drooping of the leaves. You should always make sure that the medium in which you grow your plants isn't too wet or dry. It should be comfortably moist.

Another problem concerning water is that it can contain a lot of different elements and minerals, and one should be careful about what kind of water they are using. You should test your water for anything that can be harmful to your cannabis plant.


As with water, too much or not enough nutrients are a cause of stress for cannabis plants due to the mineral imbalance that prevents the plant from functioning normally. Older plants need fewer nutrients than younger ones and are more likely to show signs of nutrient stress. Telltale signs of nutrient stress are yellow-tipped, discolored, spotted leaves and stunted growth. Nutrient burns or “not burn” is a term for the overabundance of nutrients in the soil, resulting in a yellow-tipped or “burnt” leaves. A common solution for the nutrient burn is to flush the growing medium with a large amount of pH-regulated water.


PH is a scientific measurement used to specify how acidic or basic a substance is. This measurement uses a scale from 1 to 14. Pure water is neutral, being neither acidic nor basic and has a pH of 7. Everything higher than 7 is considered basic and everything below 7 is acidic.

PH affects the plant's ability to absorb nutrients because an acidic or basic solution changes nutrients fundamentally making them impossible for the plant to absorb. Many growers don't catch on to that and think that they have a nutrient deficiency problem, feeding the plant even more, which causes a whole new set of problems. So, when you see signs of nutrient deficiency be sure to check the pH levels first. Knowing the pH level of your growing medium and knowing how to control it goes a long way toward the overall health of your plant and the chances of a successful grow.

The ideal pH of the soil in which you grow your plants is 6.5-7.0. Monitoring pH level is very simple because all you need is an electronic pH reader. They are cheap and very easy to use; you only pop the probe into the medium and get a pH reading. Controlling the pH level is a no-brainer too, just buy pH-up or pH-down products in the shop and add them to the next watering. For a more natural way of controlling pH in soil use dolomite lime which has a pH of 7.



Cannabis, as all plants, has a certain light cycle which you need to follow during a grow. At its vegetative stage, a cannabis plant needs 18 hours of light and a light cycle of 12/12 in its flowering stage.

Consistency is a key to maintaining a healthy, natural light cycle, meaning that the start and end times should remain the same throughout the grow. Cannabis plants are very sensitive to changes in light, and that is one of the ways they know the seasons are changing. When you are switching from 18 hours of light to 12, you are helping your plant to mature and switch to its flowering stage.

It is very important that the cycles of darkness during the flowering period aren't interrupted because it causes the plants to abort the flowering phase and return to their vegetative phase, which will negatively affect the grow and yield. Even the smallest amount of light during the dark phase can cause stress.


Plants are good at handling minor tissue damage and if the plant is healthy, it will bounce right back from the physical damage and even strengthens its resistance. However, major tissue damage or continued minor damage will have a negative effect on the plant and cause stress because the plant will spend its energy on healing itself instead of growing.


Roots are the foundation of the plant, the place where the plant absorbs nutrients and oxygen. They are maybe the most important part of the plant to keep healthy and running because the condition of the roots has a huge impact on the overall health and growth of the plant. Roots can be hurt by light, physical and chemical damage, bacteria, mold, and you should always make sure that the root zone isn't much colder or hotter than the rest of the growing environment.

It is important to make a stable environment for the root where they have easy access to the right amount of water, oxygen, and nutrients. As mentioned earlier, a correct pH environment is crucial for proper nutrient absorption.


As a rule of thumb, your growing area should feel comfortable to you at all times and chances are it will be comfortable for your plant too. Any environmental extremes, like very hot or very cold temperatures, excessive humidity, and others, will negatively affect your plant and cause stress. The temperature level should be at room value most of the time, and proper airflow in the grow area should be considered. Humidity is also something that has an impact on the plant and shouldn't be too high or too low.

Extreme environmental changes can stop the plant from growing or worse, so take care of the plant surroundings.


There are types of beneficial stress which can help the plants growth, overall health and even increase the yield of the plant. For example, by using an oscillating fan during the vegetative phase you force the plant to move, which helps the stem to become thick and robust.

Another example of beneficial stress is plant training. Plant training is the process of managing plant growth using various applied stresses to manipulate the plant shape and size. There are many types of plant training such as low-stress training, topping, super-cropping, etc.

And although it may seem like a bad idea, getting your plants cold can actually have a positive outcome if done right. A sequence of warm days and cold nights during the last two weeks of the flowering phase mimics the natural growth cycle of a cannabis plant, helping it to produce more resin and a larger color palette.


Cannabis is a weed, a very robust and resistant plant that is easier to grow than most people think. Occasional stress to the plant shouldn’t be something to worry about, but, major or constant stress will harm it and deter it from growing into a normal, healthy plant.

Balance is the key. The plant should be in a state of homeostasis, a biochemical equilibrium; its optimal living state. To achieve that the grower should learn that the solution to most of the causes of stress is a question of balance, knowing the right amount of water, nutrients, and light with which you feed the plant. In such an environment, a plant should have no problem to flourish and grow to its full potential.