Marijuana stress is caused by imbalances of the plant chemistry. Whatever the cause, the stress starts effecting the normal function of the plant and the plant will begin to show signs of problems.
Marijuana plants like to have a consistent envronment which doesn't change much from day to do. You will want to incorporate any changes slowly to avoid stressing your plant.
Main Causes of Cannabis Plant Stress:
- Water Stress: Over or under-watering will cause plant leaves to droop. An over watered plant has firm, downward curling leaves, while an under-watered plant looks wilted and dry.
- Nutrient Stress: When a plant is given too many nutrients, or not enough, then it starts showing signs of stress. This is caused by mineral imbalances which prevent the plant from carrying out it's normal functions. Common signs of nutrient stress are burnt brown or yellow leaf tips, yellowing leaves or other abnormal coloring/spotting, leaves falling off, and slowed growth. As plants get older, they need less nutrients and may be more likely to show signs of nutrient stress. An older marijuana plant will need less nutrients than a younger one.
- pH of Root Zone: pH is a measure of how acidic or alkaline a substance is. In order for your plants to get all their nutrients, their roots need to have an environment with the correct pH. If the roots are exposed to the wrong pH, they won't be able to absorb all their nutrients and may start showing signs of nutrient stress. Therefore it's important to check and adjust the pH of your water to maintain a proper root pH.
- Irregular Light Cycles: Marijuana plants need 18+ hours of light a day when they're in the vegetative stage of their life, and a 12/12 light schedule when they are in the flowering stage. It's important that any 'start' and 'end' times remain consistent thorughout the grow. It's also imporant that the plants do not get any light during their 'dark period' of 12 hours during the flowering stage. When the plant gets light at inappropriate times, it's possible that the plant will turn 'hermaphrodite' (show signs of being male even though it's female). The light stress may also prevent the plant from providing the best yields even if it shows no symptoms.
- Plant Tissue damage: Any damage to the plant itself. Most times, if the plant is healthy otherwise, it will bounce right back from any physical damage. It's inevitable that you will eventually damage one of your plants, so don't beat yourself up about it too much.
- Root Health: Roots are the foundation of your plant, and it's important that your plant's root are given a proper environment. Roots can be hurt by light, physical damage, chemical damage, or certain kinds of bacteria. It's important to provide the roots with an environment where they have ready access to oxygen, water, and the right amount of nutrients. As I mentioned earlier, roots should be maintained in the correct pH environment to ensure proper nutrient absorption. It's a good idea to make sure the root zone never gets much hotter or colder than room temperature if you want to ensure that the roots are able to absorb the most oxygen out of the water. Maintaining a comfortable root temperature will also help prevent the growth of bad bacteria.
- Environmental Extremes: In general, your plant's grow area should feel comfortable to you at all times. You want to try to maintain a consistent temperature if possible. If you think your grow area feels stuffy, hot, or cold, your plant probably does too. There should be good circulation/airflow around the plants, and the humidity should never get too high or low. When there are extreme changes in the environment, your plant may temporarily stop growing. If the environmental extreme worsens or doesn't get better, your plants will start showing physical signs of stress and may even die.
If you think that your plant may be showing signs of stress, check out my Marijuana Problems and Symptoms pages for a more details on how to prevent and resolve the problem.