By Luke Sumpter

Browse Deficiencies
Browse Deficiencies
Browse Deficiencies


Growing cannabis is a therapeutic act that takes quite a lot of attention to detail. One of the requirements to successfully grow a large cannabis crop of good quality is applying the right concentration of nutrients. If your plant begins to lack the required amount of nutrients during any point of the grow cycle, it may begin to exhibit symptoms of deficiency. If left untreated, these deficiencies may cause harm to the plant’s health and reduce yields.



One of the most important nutrients that your cannabis plants need is nitrogen. Nitrogen is vital for plant health because it is a major component of the green pigment found within plant leaves known as chlorophyll. Chlorophyll plays a crucial role in photosynthesis, the process by which plants convert sunlight into energy in order to survive. Nitrogen also serves as a major component of amino acids within plants, which are the building blocks of proteins. Nitrogen is also an important component of nucleic acids like DNA, which plants need in order to grow and reproduce.


It is quite clear to see how important nitrogen is to your cannabis plants and why a deficiency could be so damaging. Luckily, nitrogen deficiency is quite easy to detect if you know what to look for.

One of the key signs of nitrogen deficiency within your weed plants is yellowing leaves. The older and lower leaves on your plants will start to become yellow, wilt, and drop off. This is because the younger leaves higher up the plant will start to steal the nitrogen from these older leaves. The plant prioritises higher leaves as they receive the most light, contributing greatly toward photosynthesis.

This may not always be a concern. It is normal for these lower and older leaves to start becoming yellow and dropping off towards the end of the grow cycle as nitrogen is diverted toward the buds. It is time to worry when your plant’s leaves start to yellow and drop off rapidly during the vegetative phase. If this yellowing starts to move up the plant in a climbing manner, then a problem is most likely present.

A solution to this problem is to provide your plants with a balanced nutrient product. There are many formulas available that provide an array of key nutrients to your plants, making sure that nitrogen levels are kept at a healthy level all the way through the vital vegetative phase.

Nitrogen deficiency table leaf


Some novice growers may be shaken at the sight of nitrogen deficiency symptoms, causing them to go overboard when adding nitrogen to their soil. However, be forewarned: the pendulum can swing the other way when it comes to nitrogen, with too much also causing a problem in plants.

When a grower accidentally puts far too much of the nutrient into their soil, it can cause the phenomena of nitrogen toxicity. During the vegetative phase of the grow cycle, it is rare that plants will develop nitrogen toxicity unless a huge amount is given to them. Nitrogen toxicity is more common during the flowering phase, as plants require lower levels of nitrogen at this point. Symptoms of toxicity can manifest in shiny leaves, much darker green leaves, weak stems on plants, much slower overall growth and clawing of leaves. Clawing is a typical occurrence that involves the tip of leaves losing vigour and folding downwards, resulting in a claw-like appearance.

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