How to Keep Cannabis Plants Healthy – Growing Guide

How To Keep Cannabis Plants healthy

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For anyone who has ever grown or catered to the needs of cannabis plants will understand the true meaning of a healthy yield. In particular, a yield that helps them taste the fruit of hard work. Though sometimes, the naivety of growers leads to a bad growing season.    

As a result, a major group of cannabis growers either end up giving up the profession altogether or seek the expert advice of professional cultivators to address lingering issues. And amidst all this, there’s one thing our fellow cannabis enthusiasts learn – the art of keeping the plants healthy. More importantly, something that all novice growers look for – how to keep a cannabis plant healthy? Read on to find out more. 

Stressors on Cannabis Plants  

Just like humans, plants also go through stress. And the stress-causing factors are largely environmental or physical. They come in the form of water, high or low pH, excessive nutrients, age, irregular light cycles, environment, and insects. Being aware of all these factors is extremely crucial. 

While some of them in moderation will lead to a good yield, anything excess or low can cause the plant health to deteriorate. This is to say that plants do not like to be surprised. A normal and familiar day is what they seek. As soon as your cannabis plant experiences a change, they deter from the path of health to deterioration. 

So, it is extremely crucial to understand the potential of stress factors. Here’s a list of factors plants will witness during the development stage: 

Nutrient Stress

This type of stress occurs when you add an excessive or imbalanced amount of nutrients to the plant. Being able to understand what nutritional value means for your plant will always help you stay one step ahead. 

pH Stress 

The pH value will determine the plants’ ability to absorb water and other nutrients. If the pH value is really high or extremely low, the roots will automatically lock out the minerals your plant needs to grow. 

Water Stress

The stomata cease to close when you are either watering your plants excessively or simply not keeping them hydrated enough. It is extremely essential to water your plants in a consistent manner. 

Exterior Damage

The chances of external damages are unavoidable, but you can prune your crop carefully to ensure the branches stay intact. As for a broken branch, immediate repair is the key to avoid any further problems. 

Insects Stress 

Be it a disease caused by biotic stress or insects attacking your crops frequently. Both the stress factors will cause your plant to suffer. So, you have to understand what type of insects attack which part of the plant. You have to constantly check for patterns.

For instance, some insects feed on the leaves while others feed on the stalk. Once you recognize the type of disease and insects killing your plants, it will be easier for you to start the treatment plan. 

For indoor plants, pretty much everything is under your control. The only exception, in this case, is outdoor plants which require extra care because of environmental factors. 

Use High-Quality Water

The quality of water you use to maintain the health of your plant determines the strength of your yield. So, take some time to figure out the source of water.

In other words, look for contaminants that are most likely hindering the growth of your yield. For instance, lead, mercury, microbiological contaminants, harsh minerals such as nitrates, and pesticides. 

In order to do the same, get a water quality report, identify the contaminants in your water, and then identify the best water chemistry for your plants. To put things into perspective, here’s a brief explanation. 

Plants are not good with water containing high levels of magnesium and calcium. This form of water is termed hard water. The same goes for water that you receive through municipal outlets. The only difference being that municipal water mainly consists of chloramine. Another ingredient that will most likely kill your cannabis plant. 

As a general rule, any form of water will contain some or the other contaminating chemical. To ensure your crops get the best form of water, include a filter. Filtration agents such as reverse osmosis, water softeners, and carbon sediments will allow your plants to absorb what’s needed. 

To put things into perspective, here’s a detailed explanation of how each filter works: 

marajuana leaf care

Carbon or Sediment Filters

These filters are essential for water that contains high levels of chloramine. A carbon filter will effectively block chlorine and other large sediments while keeping the PPM count in check. Not only this, but these filters also help reduce water waste to a great extent. 

Reverse Osmosis Filters

An RO filter will remove 96% of the contaminants and help produce water free of chemicals, dirt, and several other contaminants. The only problem with this filter is its capability to produce wastewater as a byproduct. In other words, you might need to add pre-filters like the one mentioned above to increase its effectiveness. 

Water Softeners 

You can use this as a pre-filter for water purification. All you have to do is place it before the RO filter to replace sodium chloride with calcium and magnesium. 

Once all the filters are in place. And you are ready to use high-quality water for your plants, check the temperature and oxygen levels. Because dissolved oxygen will affect the overall health of your crops. The DO will also determine root growth, nutrient intake, and growth of bad bacteria. This is why it is crucial to either use cold water or maintain the temperature at 72 degrees Fahrenheit with a DO percentage between 5-8%.          

Add Nutrients as per Requirement

Every cannabis yield goes through different stages of growth. The first being vegetative followed by flowering and the full development phase. You might be wondering what these stages have to do with the nutritional value. 

Well, if you pay attention closely, you will realize that with every stage the nutrient requirements also change. For example, your cannabis plants will absorb increased amounts of nitrogen in the early stages. On the other hand, they will relatively use a higher concentration of phosphorus during the flowering stage and fewer amounts of nitrogen. This is why it is vital to focus on the nutrition formulae you purchase from the market. 

In addition to this, you need to understand the efficacy of minerals. Simply put, not all minerals are identified as important for the growth and development of the plant as the ones mentioned below. 

  • Hydrogen
  • Nitrogen 
  • Carbon
  • Oxygen
  • Calcium
  • Phosphorus
  • Potassium
  • Sulfur
  • Chlorine
  • Zinc
  • Copper
  • Nickel

All these nutrients make up 90% of the plant. In particular, oxygen, carbon, and hydrogen in the form of water and air. The other nutrients are added to the plant in the form of minerals. You can commonly find these in concentrated liquids and solid salt-based powders. You just have to add these sources of minerals in a correct ratio to your crops. 

If you’re not confident about the ratio, follow Liebig’s Law of the Minimum. The law states that the growth of a plant is not determined by the resources you have but by the scarcity of resources used in a balanced proportion. This is essentially a calculative way to say “the more the merrier is not always good.” Just like a balanced diet for humans, plants too require a properly maintained minerals diet.         

Focus on Transpiration Before Irrigation

For those who do not understand the concept of transpiration before irrigation, here’s what you need to learn. Often people come up with questions: how many times do I need to water my plants in a day, or how much water should I give to my cannabis crop? Well, the answer is not easy but somewhere related to the process of transpiration. How? Let’s find out!     

You see, during nighttime, transpiration stops. In contrast, the stomata beneath the leaves open for transpiration in the morning. This literally means that you have to stop watering your plants during the night. Also, it’s a bad idea to water your plants early in the morning. Instead, you must wait for an hour or more for the plants to begin the process of transpiration. And this is the exact point of time to water your cannabis crop. 

For more details on how to water your cannabis plants, here’s are some easy tips:

  • To determine the point of hydration, pick the container holding the plant frequently. For example, weigh your plant when it is dry, when some of the water has evaporated, and when the plant is fully saturated. This way, you will understand how much water you need in order to maintain optimum levels of hydration on a regular basis. 
  • If you are regularly adding nutrition to your crop, you will check two things. One, the ratio of nutrition (as discussed above), and two, the percentage of nutrition drained out with water. Frequent runoffs say about 10-20%, will keep the plant’s toxicity levels in check. However, without sufficient water drainage, the salts in the nutrients will build up and cause the plant health to deteriorate. Similarly, if you are not adding nutrients, you will be required to check the number of runoffs. The less the nutrients, the fewer the runoffs will be. 
  • Touch the soil medium to water your plants again. In other words, the top 2.54 inches of the soil should be completely dry before you begin watering your plants again. 
  • For advanced cultivation techniques, use water measuring meters. These digital sensors will allow you to log data and build an efficient plant watering routine.  


Adjust the pH value according to the requirement of the plant. Do not let your crop flourish in a less acidic environment. Unlike the human body, cannabis plants need to grow in a slightly acidic habitat. So, it’s recommended to keep the soil pH value between 6.0-6.8 and 5.5-6.5 for hydroponics. 

Also, take note of how you feed your plant. After all, the solutions and water you use determine the pH concentration too. And in order to do the same effectively, check the pH value of water and other mineral solutions using litmus paper or a pH meter. 

If your plant does not meet the recommended ratio, adjust it with the help of acids available in nearby nurseries. It is most likely that even after applying extra cautionary measures, you will most likely get confused. But the best part is that there is no exact no for pH values. You just have to keep the ratio in mind and monitor it as frequently as you can. If you do the same, your plant will become capable of uptaking the correct amount of minerals. 

Rest assured, when it comes to concentration levels, it is always wise to check pH first, as most mineral solutions will have different values – from highly acidic, to low, and moderate. Once you determine the right pH you will allow your plant to absorb maximum amounts of nutrients and water. 

However, as soon as the pH levels skyrocket or fall below the required level, the roots will lock the minerals from uptaking anything. And you don’t want that to happen at any cost. So, don’t think of it as a herculean task, simply use a pH meter, measure the value as per requirement. And then go ahead and add whatever you need into the soil. 

Final Words

It’s crucial to notice the changes your cannabis crops go through. Be it something as little as light absorption or water retention. All these factors, whether big or small, will help you monitor the health of your plant. Not only this, but it will be easier for you to identify the problems related to cannabis cultivation before the entire crop goes bad. As for those who are growing cannabis for medical purposes, get a medical marijuana card in Oklahoma or your respective state. And grow increased limits while keeping all the above-mentioned points in mind. 

Zak Voss, the founder of The THC Times, brings over 15 years of experience in the cannabis industry, blending his engineering background with extensive legal and technical expertise. Renowned for his consultancy in cannabis legalities and indoor growing environments, Zak is a vital guide for navigating the complex cannabis landscape.