Cannabis Calcium Deficiency: As humans need different types of minerals and nutrients to stay healthy, the same goes for plants. If you are growing cannabis yourself, then you might have to take extra care of it else it won’t reward you with the desired quality of strains. It doesn’t matter if you are a professional grower or someone who is new, you can face issues like calcium deficiency in plants, and it is definitely a big problem, to be honest.
Though if you are able to identify and act quickly, the effects can be reversed. So, it is important to know about cannabis calcium deficiency, what it looks like and what measures one should take to not face this problem again. Read this post till the end, as we have shared everything related to calcium deficiency in plants and how you can solve this problem. Why Do Cannabis Plants Need Calcium?
Calcium is required by cannabis plants since it is vital for the plant’s health and growth. Calcium is an essential component of cell walls and aids in cell development. It also promotes the delivery of other vital nutrients, such as nitrogen and phosphorus, all across the plant. Furthermore, calcium is necessary for the formation of strong and thick roots, which are essential for the plant’s general health and strength.
Cannabis plants that lack calcium may endure slowed growth, discolored leaves, and deformed new growth. It can also make the plant more sensitive to diseases and pests. So, always make sure your plants are getting enough calcium along with other important nutrients so they can grow perfectly fine.
Signs of Calcium Deficiency In Plants
You will be able to identify the deficiency of calcium in your plants by paying attention to the symptoms. If you start noticing something unusual with your plant then there is definitely something wrong with it. Since every issue shows some symptoms, if you know about them, then you will be able to identify the actual problem pretty easily.
Every plant shows different symptoms, and there are chances that some plants might show a single one while other shows multiple signs. The age, location, placement, strain, and many other things play an important role in the development, growth, and signs a plant shows when there’s a deficiency of something like calcium, sulfur, etc.

Discoloration of Leaves – The first-ever signs of calcium deficiency in cannabis plants will start appearing on the leaves. You will notice that the leaves that are at the bottom of the plants have started turning yellow. The effect starts from the bottom and then goes to the top. So, if you are quick enough to identify the issue, you can stop it from spreading to the whole plant.
Stunted Growth – You might start noticing that the plant has stopped growing further or not growing at the same speed it used to. Calcium plays an important role in forming new stem cells, and if the plant is not getting an adequate amount of calcium, then it will not grow. It might take a week or two for the plant to start showing recovery effects.
Twisted Leaves and Branches – If the edges of leaves and branches have started twisting or distorted, then it can be a reason for calcium deficiency too. The plant must have the strength to hold all the branches and leaves while standing straight, and if it doesn’t have enough calcium, the entire plant will start twisting.
Poor Root Development – As we all know, the roots are the ones that transfer all the nutrients from the soil to the entire plant; if there’s no calcium left in the soil, the roots will have issues executing their work. There will be no formation of new roots, and it will stop expanding, and the current roots will start rotting too.
More Prone To Diseases and Pests – Calcium is important for the overall health and strength of the plant, so a deficiency can make the plant more susceptible to diseases and pests. If you start noticing more insects on your plant and leaves, then it is high time you start focusing more on the nutrients and pH level of the soil.
How To Fix Calcium Deficiency In Marijuana Plants [GUIDE]
Don’t worry if your plant is having calcium deficiency because this problem can be fixed pretty easily. Remember that the solution to this problem generally depends on various factors such as the age of the plant, temperature, how long this problem persists, and many more. Not only this, but you must pay attention to the deficiency and toxicity of other nutrients as well because calcium solely is not responsible for the growth and death of a plant.
Below we have shared some important measures that every plant grower must take in order to fix calcium deficiency in cannabis and other plants.
1. Using a fertilizer that is high in calcium can help to correct the deficiency. You must follow the instructions mentioned in the pack to use it wisely.
2. Calcium is most available to the plant when the pH level is between 6.0 and 7.0, so adjusting the pH level to this range can help to fix the deficiency.
3. Make sure plants are getting adequate water, but not too much water. Over-watering can cause the soil to become waterlogged, which can prevent the plants from absorbing calcium.
4. Provide the plant with the right amount of light, and make sure that the light is not too intense. Make the best use of sunlight to improve the photosynthesis process.
5. Make sure that the temperature is not too high or too low, as this can affect the plant’s ability to absorb calcium. Use artificial lights to maintain the proper growing temperature.
6. Calcium works in conjunction with other nutrients, so make sure the plant is getting enough of all the essential nutrients, like sulfur.
NOTE: You might be able to fix the calcium deficiency problem by following the methods we’ve mentioned above, but it is really important to keep checking the soil and plant’s health often. There are various factors that influence the development and growth of a cannabis plant, and it is not always about the nutrients and vitamins.
Remember that other elements like nitrogen, phosphorus, and potassium are required by every plant in the maximum quantity, following other nutrients like calcium, magnesium, and sulfur. If you want, then you can connect with a professional weed grower and get directions on use for nutrients and when your plant has a deficiency for something.
This will ensure you are doing the right thing and better the growth and life of your plant.
Calcium Toxicity vs Calcium Deficiency In Plants
Calcium Toxicity – Well, if your plant is lacking something doesn’t mean you can overdo it. Providing nutrients like calcium in excessive quantity is also bad for the plant, and it can cause various issues. The condition is called “toxicity” or “hypercalcemia”. Just like the deficiency, your plant will start showing signs of excessive calcium and they include blackness or brown leaves, low fruit and flower production, wilting leaves and many more. It is important to properly diagnose the problem before taking any corrective action because these issues can be caused by other factors as well.
Calcium Deficiency – It is important to note that deficiency is caused when growing something in a limited area. Plants that grow outside in the ground get proper nutrients themselves, and you have to pay very little to no attention to their growth. However, if you don’t pay much attention to the deficiency signs of calcium, it can lead to the death of the affected tissue.
There are various reasons behind the lack of calcium in the soil, and some of them include excessive watering, not maintaining the correct pH level, using the soil of poor quality, and many more. Although these problems can be fixed pretty easily and you can follow the steps we’ve mentioned above.
Also Read: Cannabis Zinc Deficiency
FAQs Related To Cannabis Calcium Deficiency
Can Cannabis Recover From Calcium Deficiency?
Not only cannabis but almost every plant can recover from calcium deficiency. The only requirement would be doing the right things at the right time to get things done. Remember that recovery can be slower for some plants depending on how long the deficiency has been present, the age of the plant, and what products you are using to treat it.
What Does A Calcium Deficiency Look Like In Cannabis?
Calcium is the mineral that is responsible for the new growth of the cells in a plant, so having a deficiency of it will cause the plant and leaves to bend. The color of the leaves will change to yellow or brown. Not only this, but the roots will not form properly, and the growth of the entire plant will stop or will be gradually low as compared to the time when it had all the nutrients.

What Is A Good Source of Calcium For Cannabis?
If your cannabis plant needs calcium, then you can use products like calcium carbonate, calcium nitrate (available as a spray), eggshells, dolomite lime (can be used to adjust soil pH and provide calcium to the plants), gypsum (good source of calcium and sulfur). You can also buy fertilizers that come with calcium and add them to the soil.
Does LED Grow Lights Cause Calcium Deficiency?
The grow lights used on the plants do not influence the nutrients and things that a plant absorbs from the soil. So, the lights won’t cause calcium deficiency as it is used mainly for the photosynthesis process. However, some factors like temperature, humidity, and light intensity can affect the plant’s ability to absorb nutrients from the soil.
How Can I Make My Soil Calcium Rich?
There are various natural ways available by which you can make your soil rich with calcium and other nutrients so can plants can grow perfectly fine. Some of the best ways are adding lime, crushed eggshells, bone meal, and calcium-rich fertilizers to the soi. You might have to conduct a soil test to determine the current pH and nutrient levels before adding anything to it.
Final Words
So, this is all about how calcium deficiency affects your cannabis and other plants and why it is important to fix this issue asap. There are literally more ways to solve this problem, but we have mentioned only the working ones here. Many professional growers share their opinion and we have tried to assemble all of them on this page.
If you know something that we might have missed mentioning here, then do let us know about it. Also, you can keep visiting this page to learn more about the calcium deficiency in cannabis plants and how you can fix it. We keep adding more information about the topic and ways to solve the cannabis calcium deficiency issue.