How to Recognize and Fix Cannabis Deficiencies

  • June 11, 2022
  •  Comments : 0
  • Last modified on June 24th, 2022 at 9:11 am
Cannabis Deficiencies

It is essential to know the signs of nutrient deficiency when growing cannabis. The cannabis plant becomes stressed and susceptible to mold, bugs, pests, and other pathogens when they do not get the right amount of nutrients. They may have stunted growth, resulting in reduced yields. It is important to quickly fix any symptom of cannabis deficiency before it destroys the plant.

How to Recognize and Fix Cannabis Deficiency

The signs of cannabis deficiency are quite obvious. They often present themselves as leaf discoloration. There are more signs of cannabis deficiency that can be avoided when you are attentive to your plant. Being careful with the pH level of the nutrient-water solution you give the plant can also help you prevent or fix any deficiency.

As you grow your cannabis plant, it will continuously communicate with you. Below are major cannabis nutrient deficiencies to take note of and how they can be fixed.

  1. Boron deficiency

 Boron deficiencyThick or abnormal growth tips are the first sign of boron deficiency. This growth is accompanied by the appearance of yellow spotting on new leaves. The upper leaves will have abnormal or slow growth. Boron should be absorbed in the lower pH ranges. Your cannabis plant may not be getting the right amount when the pH level is too high.

Luckily, boron deficiency can be solved. The best way to fix it is to ensure that the pH level is constant. This means 5.5-5.8 for hydroponic growth.

2. Calcium deficiency

It can be hard to detect calcium deficiency in the cannabis plant. However, signs that can be an indication of a plant lacking in calcium may include curled leaf tips, distorted or small leaves, stunted growth, small brown spots, crinkling, or dead spots. Calcium deficiency often appears together with iron and magnesium deficiency.

Flushing the plant with clean, pure pH-neutral water is the best way to restore calcium deficiency. Thereafter, you can supply the nutrient-water solution again. The solution can also be supplemented with Cal-Mag. This is to prevent magnesium and calcium deficiencies in the future.

3. Magnesium deficiency

 Magnesium deficiencyThe cannabis plant will have its outer edges and veins develop a light green-yellowish color when it is lacking magnesium. The nutrient magnesium is mobile. It can move from old leaves to new ones. Magnesium is unlike iron, and its deficiency occurs when the pH level is too low. This commonly happens due to the pH sweet spot being 5.5-5.8. Adding a magnesium supplement to the plant will not help because magnesium is already present in the plant’s root but cannot be absorbed. Increasing the pH to about 6.0 is the best way to get the magnesium absorbed. Do this until it is resolved, and then the pH should be lowered to 5.5-5.8 afterward.

4. Iron deficiency

Iron deficiency in the cannabis plant can be easily identified once the leaves completely turn yellow. It must be noted that iron deficiency in the plant is similar to that of magnesium. However, the newest leaves on the plant will be yellow with an iron deficiency. When the pH level is around 7, which is too high, the plant does not absorb iron.

Seeing iron deficiency in the hydroponics systems is not common. The best way to restore your plant in case you come across this sign is by flushing the hydroponic system. Do this using pH-neutral water. Adjusting the pH to the right levels can then follow.

5. Copper deficiency

There are many signs of copper deficiency in the cannabis plant. It can be identified when the leaves have purple or dark blue undertones. The edges and tips of the leaves turn yellow and also become shiny. Buds growing slowly or that does not ripen is a sign of copper deficiency. In most cases, copper deficiency is a result of an incorrect pH level. To fix it, make sure that the pH level is tested and adjusted accordingly.

6. Nitrogen deficiency

Unlike iron deficiency which will make the leaves turn yellow, nitrogen deficiency will make the older, lower leaves of the plant turn brownish-yellow. The leaves will eventually wilt away and die. Nitrogen is a mobile nutrient just like magnesium, it travels from one leaf to another. It plays a major role in photosynthesis, which creates the green pigments in plants.

The newer green leaves will have enough nitrogen while older ones will change to yellowish-brown, crinkle, and eventually die. The cannabis plant can become deficient while producing buds in the flowering stage. It is not strange for the plant to lose nitrogen at this stage. However, nitrogen deficiency is not what you want in the vegetative stage.

Nitrogen deficiency is best avoided or fixed by ensuring that you give your plant a high-level nitrogen nutrient. Your plant may not be taking in the nitrogen if the pH level is too low.

7. Zinc deficiency

The cannabis plant suffers from zinc deficiency as well. This deficiency will make the plant’s veins turn yellow. There will also be the discoloration of the leaf tips until they begin to die. Stressful conditions or plant shock are the causes of some zinc deficiencies.

The cannabis plant will always bounce back once that is over. Incorrect pH level is mainly the reason why zinc is not absorbed. At a higher pH level, zinc gets locked out. As a result, the pH level must be adjusted to fix zinc deficiency.

General Solution to Fixing Cannabis Deficiency

When treating cannabis deficiency in the plant, it is essential to begin with the verification of the growing media’s pH level. The ideal range for cannabis is 5.5 and 6.5. it is also a suitable range for most flowering and fruiting plants.

In case the pH is out of range, it is recommended you flush the growing media. This should be done with a flushing agent or clean water.


Just like every other living thing, cannabis requires vital nutrients for survival. In case there is any deficiency, ensure that the pH level is adjusted to fix it.

Mr. BC Seeds
Mr. BC Seeds is an over educated old school hippy who has been involved in the cannabis industry since the 1970's. He is one of the most experienced marijuana breeders in Canada if not the entire world. He was the first to use the most advanced breeding techniques in 2008 to create 42 of the world's strongest cannabis strains. He has been writing in-depth articles about cannabis in Canada for decades and looks forward to continue bringing you cutting edge cannabis strains for the decades to come. Mr. BC Seeds uses a "pen name" because he still travels the world collecting cannabis strains and continues researching cannabis in laboratories of non-legalized countries.
Posted in Cannabis and tagged Cannabis

Leave a Comment


Boxed Layout only