Cannabis Calcium & Magnesium Deficiency - How to Spot (and Fix!) Them

Calcium (Ca) and Magnesium (Mg) are both essential elements needed for your cannabis plant's growth and flower development. They are seen as the most important non-primary cannabis nutrients, and are the most common to cause a deficiency when growing weed hydroponically.

In this article, we will go over the functions of both Ca and Mg in the cannabis plant, how they interact, how to determine if you plant is receiving adequate amounts, and how to fix any issues cause by Calcium or Magnesium deficiencies and/or toxicities.

Understanding Signs of Nutrient Deficiency/Toxicity

First it's important to understand that signs of nutrient deficiency/toxicity will always be first shown on the cannabis leaves. But, most of the time, the leaves depict issues that are happening within the root zone, or with the plant internally.

You should also understand the difference between "Mobile" and "Immobile" elements within the plant. Mobile elements (N, P, Mg, K) are nutrients within the plant that can easily be moved from older leaves to younger parts of the plant. This means that when the cannabis plant becomes deficient in a mobile nutrient, it will start to show physical signs of deficiency on the lower portion of the plant (older leaves) first!

Immobile elements (Fe, Cu, Z, B, Ca, Mn) lack the ability to be translocated once absorbed into the cell. As a result, any symptoms of their deficiency will typically manifest at the top parts or growing tips (newer growth) of the plant. If a nutrient is partially mobile (Cu,Z) then you will see it throughout the entirety of the plant.

Cannabis plants prioritize their growing tips. Hence, if the required nutrient levels aren't met or maintained, they will transfer those mobile elements from the lower leaves to the top leaves. This is why you usually notice mobile element deficiency issues towards the lower parts of a weed plant first: plants sacrifice mobile nutrients from the bottom, and relocate them to the more important growing tips, where nutrients are needed most.

How Calcium/Magnesium Deficiency Affects Your Cannabis Plants?

Calcium and Magnesium, also refer to as “Cal-Mag,” are both crucial nutrients necessary for the cannabis plants to flourish!

Cannabis Calcium Deficiency

Cannabis Calcium deficiency is not common in soil or outdoor grown plants.

In contrast, this element is needed in high amounts when growing hydroponically, and thus cannabis Calcium deficiency is the most common amongst indoor/hydro growers.

Calcium Functions

Calcium serves a multitude of vital functions in cannabis plants. It is essential for growth (meiosis: plant cell division). It also facilitates nutrient uptake, regulates the opening of stomata and transpiration, and helps ensure that sugars and proteins are flowing throughout the plant properly. Calcium also helps regulate enzymes and hormonal activity within the plant, and can help fight off stress!Since Calcium is indispensable for growth, you may see a cannabis calcium deficiency appear at times when the plant is in need of high energy, such as when transplanting clones or seedlings, or during the flowering stage.

Symptoms

Remember that Calcium is an immobile element, so the symptoms of deficiency always show towards the top of the plant! Some physical signs of cannabis Calcium deficiency can be yellowing leaves, brown spotting on leaves, and leaf cupping - all seen on the upper portion of the plant or branches!

Negative Effects

If your cannabis plant is suffering from a calcium deficiency, it may lead to:

• lowered nutrient uptake
  
• lowered levels of transpiration (which can cause wilting)
• or slow flower development during mid blooming stage

Calcium Toxicity

Humidity and air movement play a factor in Calcium uptake. If the grow environment is too humid, or there isn't adequate air movement around the cannabis plant, there's a risk of calcium overload or "toxicity" as the plant may struggle to efficiently absorb and utilize the available calcium.

Certainly, robust cannabis seeds tend to exhibit greater resilience when confronted with challenges. Unsure where to find top-notch seeds or clones? Consider this trusted pick, trusted by countless Hey abby growers for its dependable quality and diverse strain options.

Magnesium Calcium Deficiency

Magnesium is another crucial element that is needed in high amounts, especially in hydroponics systems.

Magnesium Functions

Magnesium plays a crucial role in various vital processes within cannabis plants, including:

• photosynthesis
  
• conversion of sugar to proteins
• chlorophyll production
• development of a robust cell structure
• utilization of Phosphorus
• and general nutrient uptake

Symptoms

Since Magnesium is a mobile element, the signs of its deficiency typically show towards the bottom of the plant. Magnesium deficiency will often show itself as yellowing, spotting, or tiger-striping of lower leaves.

Cannabis Magnesium deficiency can often be confused with Potassium deficiency. However, since they are very different nutrients, it is important to diagnose the issue properly. If you notice burnt spots or dead tissue around of the leaf edges, but never saw the leaves turn yellow, the problem is most likely a Potassium issue, instead of a Magnesium one.

Negative Effects

Magnesium deficiency can cause increased sensitivity, lower rates of photosynthesis, slow or stunted growth, and restricted nutrient uptake/utilization.

How to Fix Clacium or Magnesium Issues on Cannabis Plants?

There are a few different approaches fixing cannabis Calcium or Magnesium deficiencies.

First and foremost, make sure you’re providing the plant with a well-balanced nutrient or feeding regimen. I have seen the common mistake of growers trying to create their own nutrient mix, blending different brands and products while adding in “bloom boosters” and “growth enhancers,” but only to the detriment of the plant.

Many growers do not realize that this leads to over-feeding, which in turn brings massive nutrient imbalances and deficiencies. When growing cannabis, MORE IS NOT BETTER! It’s best to use fertilizer from one brand, and follow the feeding chart provided by that company.

Another approach is to ensure your plant can effectively utilize the Cal-Mag already provided. To achieve this goal, you need to keep the feed PH level in a proper range, avoid overwatering, ensure adequate air moving around the plants, and keep the humidity at a reasonable level. If you have all the previously mentioned areas covered and still observe issues, then it may be time to apply a Cal-Mag supplement!

Most nutrient brands have their own “CalMag” supplement, and I recommend sticking with the product from your chosen brand. It's best to use pre-mixed products containing both Calcium nd Magnesium in the correct ratio. Make sure to follow the instructions listed and provide the proper dose – and again, MORE IS NOT BETTER!

Additionally, I have found great success in using foliar feeding for cannabis plants deficient in Calcium and Magnesium. Foilar feeding involves applying a nutrient rich spray directly to the plant's leaves, allowing for quick absorption of the deficient nutrient. However, foliar spraying treats the symptom, not the root cause. It should be used as a tool in conjunction with supplementation of the necessary nutrients.

Nourish Your Plants with the Finest: Hey abby Cannabis Fertilizers

If you’re looking for a simple way to provide your cannabis plant with all the necessary nutrients, at levels strong enough to provide plants with everything necessary for a large and potent yield… Look no further! At Hey abby, we provide our growers with the best quality, highly concentrated nutrients for both hydro & soil grow, while keeping an unparalleled ease-of-use!

When you purchase a Hey abby hydro grow box, you’ll receive a free grow supplies package, including enough cannabis nutrients for a full growth cycle.

With only two different ingredient packs to added to the water, there is no need to come up with a feeding chart, or experiment with different nutrient levels. You won't need to purchase extra additives, or even waste time trying to find the nutrients - they get delivered right to your door with your grow box!

If you put Hey abby nutrients packs in comparison to other "leading brands," you will see how much higher the actual mineral concentration is. For example, if you look at the nutrient line from other popular companies, you will notice that they use three different bottles, to produce a COMBINED 12% nitrogen - VS - Hey abby nutrients contain 22% nitrogen.. That's almost 2X the amount of nitrogen available to plant, while only using 2 ingredients!!

Plus, for our Soil Edition growers, we’ve also introduced organic soil specifically tailored for optimal results.

Conclusion

In conclusion, taking care of your cannabis plants requires more than just water and sunlight. It's a delicate dance of nutrients and environmental factors, a symphony of care that brings out the best in them.

The cannabis calcium&magnesium deficiencies can be challenging, but with right fixes, they're also opportunities for growth, both for your plants and your skills as a cultivator.

You May Also Like

Cannabis Leaves Curling Up or Down (Causes and Solutions)

Cannabis Nutrients: What Your Plants Need and When to Feed Them

How to Clone Cannabis with 7 Easy Steps (& Transplant Them)