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Nitrogen Deficiency in Cannabis

nitrogen deficiency cannabis

Nitrogen deficiency in cannabis is actually quite easy to spot, leaves turning yellow during flowering and fan leaves turning yellow during veg are key signs. Find out all the symptoms, effects and discover how to solve a cannabis nitrogen deficiency.

What does nitrogen do for cannabis plants?

Since nitrogen is a mobile nutrient, it can move across the plant as needed. Cannabis plants require nitrogen to keep their leaves green and generate energy from light. Nitrogen helps with photosynthesis and keeps new leaves turn green. The plant “wants” to provide the most recent, youngest leaves precedence in getting light because they receive the most light. Nitrogen boosts plant growth; therefore, growth would come to a standstill quickly.

How to identify nitrogen deficiency in cannabis

Cannabis cultivation is a constructive activity that demands careful attention to detail. Applying the proper amount of nitrogen nutrients is one of the conditions for successfully growing a huge cannabis crop of good quality. If your plant starts to lack the necessary amount of nitrogen nutrients at any time during its growth cycle, it may show signs of insufficiency. Should nitrogen deficiency remain unattended, it can affect the plant’s health and decrease productivity.

If you detect lower cannabis leaves are turning yellow during the vegetative or early flowering stages. Then, your plant may be suffering from a nitrogen deficit, which you must address. If your cannabis shows signs of nitrogen deficiency late in the flowering period, do not panic! In the late flowering period, low nitrogen levels help support optimal cannabis bud growth and enhance yields!

Common symptoms of nitrogen deficiency

Nitrogen deficiency in cannabis signs include older, mature leaves darkening and eventually yellowing, particularly around the plant’s base. In severe deficiency, the plant will yellow, with potential discoloration and brown blotches at the outer edges; finally, the leaves will droop and fall. When cultivating cannabis, excessive nitrogen feeding might cause the following symptoms:

 1. The hue of the leaves changes to dark green.

2. Late flowering

3. Fragile stems

4. Leaves that appear to be weak bow downwards.

5. Plants have low disease and pest management requirements.

6. The result has a green tinge.


Yellowing leaves are one of the most apparent symptoms of nitrogen deficiency in cannabis plants. Your plants’ older and lower leaves will begin to yellow, wilt, and fall off. The nitrogen will be stolen from the older leaves by the younger leaves higher up on the plant. The plant prioritizes higher leaves because they receive the most light and contribute considerably to photosynthesis.

Nitrogen deficient cannabis plant
The cannabis plant’s lower leaves starting to turn yellow due to the nitrogen deficiency


Root health is critical for nitrogen uptake: roots absorb nutrients poorly when damaged by pests or illnesses. Roots grow faster than shoots. The so-called feed response to nitrogen deprivation occurs when plants search for the essential nutrient in new places. On the other hand, plants restrict root growth in the presence of sufficient nitrogen to reduce toxicity. Furthermore, if the nitrogen is there and the pH in the plant root zone is too low, indicators of cannabis nitrogen deficiency can develop. This is because your plant roots can’t absorb nutrients effectively if the pH at the roots is not right.

Abnormal plant growth

This is just another symptom of cannabis nitrogen deficiency. Plant development is delayed, and new leaves are tiny when nitrogen levels are low. This is because nitrogen encourages the growth of green, leafy plants.

Without enough nitrogen, plant growth is stunted and new leaves will grow small when nitrogen levels are low. Also, you will notice leaves turning yellow during flowering and veg without correct nitrogen levels. This is because nitrogen encourages the growth of green, leafy plants.

What causes nitrogen deficiency in cannabis plants?

Some inexperienced gardeners may be startled by the appearance of nitrogen deficiency symptoms, leading them to over-apply nitrogen to their soil. However, if there are too many nitrogen-creating problems, the equilibrium can shift in the opposite direction. Nitrogen poisoning occurs when a farmer mistakenly adds much too much of the nutrient to their soil. Plants rarely develop nitrogen toxicity during the vegetative phase of their growth cycle unless they are given a large amount of nitrogen. Nitrogen intoxication is more common during the flowering period because plants take lower nitrogen levels. Give heed to the PH content of cannabis leaves to help them become beneficial. Cannabis leaves curl up due to an overabundance of nitrogen. Their color can stay green, but the withered vegetation’s surface indicates leaves in poor condition. It is recommended to allow soil drying; then, you should use an enzyme solution for watering.

How do you solve cannabis nitrogen deficiency?

There are two methods for correcting nitrogen deficiency in the soil: organic and non-organic.

1. Organic technique

Organic methods take longer to correct a nitrogen deficiency, leading to an equitable distribution of extra nitrogen over the duration. Adding composted manure to the soil is one organic approach to adding nitrogen to the soil.

2.  Non-organic technique

When purchasing chemical fertilizer, nitrogen is a frequent plant fertilizer. Choose a fertilizer with a high first number in the NPK ratio when applying nitrogen to your plant. The NPK ratio will be 10:10:10, with the first number indicating the quantity of nitrogen present. Using a nitrogen fertilizer to repair a nitrogen deficiency in the soil will result in a considerable, massive rise in nitrogen in the soil, but the impact will fade quickly.

To correct a nitrogen deficiency as quickly as possible, water-soluble nitrogen should be used to provide the nutrients straight to the roots.

Plant problems with similar symptoms to nitrogen deficiency

Sulphur deficiency symptoms are similar to nitrogen deficiency symptoms in that the leaves turn pale yellow or light green. Sulphur deficiency symptoms, unlike nitrogen deficiency, emerge initially on the younger leaves and continue even after nitrogen administration.

The final word on nitrogen deficiency in cannabis

It is also worth noting that the cannabis plant should not be without nitrogen at any time during its development. Of course, nitrogen is most crucial for growth during the vegetative stage. Many people believe that nitrogen should be removed during the flowering period, although not the case. While there should be less nitrogen during the flowering stage, there should still be adequate nitrogen to produce essential amino acids.

If you have any cannabis deficiencies – we are here to help!

Picture of Ed Rushford

Ed Rushford

Ed Rushford’s impact on cannabis growing is undeniable. Though he tends to focus primarily on 2 areas, plant training techniques and dealing with disease, pests, and other problems, he has offered many insights into how cannabis plants live and grow. That’s not to say that Ed is unfamiliar with the complete life cycle of cannabis, from seed to harvest, but he uses his widespread knowledge to hone in on the minutia and niche areas of growing cannabis. Ed’s goal is to spread knowledge and allow for everyone to become better growers. About this Author

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