A nitrogen deficiency in a cannabis plant occurs when there isn’t enough nitrogen available to the plant. Supplying a cannabis plant with the right amount of nitrogen is crucial to keeping it growing happily, and healthily, but sometimes this isn’t easy.
In this guide, we will discuss nitrogen deficiency in a cannabis plant. By the end of the guide, you will know how to, identify, treat, and prevent it.
- What Causes Nitrogen Deficiency in a Cannabis Plant
- Symptoms of Nitrogen Deficiency in a Cannabis Plant
- How to Fix Nitrogen Deficiency in a Cannabis Plant
- Preventing Nitrogen Deficiency ins a Cannabis Plant
What Causes Nitrogen Deficiency in a Cannabis Plant
If there isn’t enough nitrogen available to our plant, via the medium, it will soon start to suffer with a nitrogen deficiency. A cannabis plant needs a lot of nitrogen during its life cycle, it is used for many things, but perhaps, the most important thing a cannabis plant uses nitrogen for is to make chlorophyll.
As the level of nitrogen falls, so will the level of chlorophyll. This is why the leaves on the lower part of your plant begin to turn yellow.
How a Cannabis Plant Uses Nitrogen
A cannabis plant will mainly use nitrogen for three things, making leaves, making stems, and making Chlorophyll. During the vegetative stage, the plant will not grow any buds (flowers) at all, just leaves and stems.
Because the plant makes most of its leaves and stems during the vegetative stage of growth, the demand for nitrogen will be highest during this stage.
Nitrogen During Vegetation
When you first learn to grow cannabis, you will look at different types of plant foods that are suitable for growing cannabis. You will find a lot of brands have a “grow” and a “bloom” nutrient.
Because the demand for nitrogen is much higher during veg, grow nutrients will have more nitrogen in them than bloom food will. As the plant moves into the flowering stage, the need for nitrogen will reduce, as the plant stops making leaves and stems, and puts all of its energy into flowers.
Nitrogen During Flower
When flowers start to from on a cannabis plant, the need for nitrogen is massively reduced. This is why when you compare bloom foods, to grow foods, you will see there is a significant decrease in the amount of nitrogen.
Nitrogen is still needed during flower to make chlorophyll, so it is still important to avoid nitrogen deficiency in a cannabis plant by giving the plant nitrogen, but in a smaller dose.
Symptoms of Nitrogen Deficiency in a Cannabis Plant
There are a few symptoms you can look out for to tell if your cannabis plant has a nitrogen deficiency. Because a cannabis plant uses so much nitrogen in veg, this is the time you are most likely to see it arise.
Keep a look out for the following symptoms
Because a cannabis plant will use nitrogen to make chlorophyll, when levels of nitrogen fall, so will the levels of chlorophyll. This will reduce the healthy green shade your plant has, and start to turn leaves yellow.
Nitrogen is a mobile nutrient, and it can be moved around the plant. So it will be taken from the lower leaves, to feed the upper part of the plant. This is why the leaves at the bottom of your plant will turn yellow first.
Because a cannabis plant uses nitrogen in large amount to make new leaves, stems and branches, a plant that is suffering from a lack of nitrogen, will not be able to make these things properly.
If a plant has stopped growing, and is short, with small leaves, it is usually a sign of nitrogen deficiency
If there is a nitrogen deficiency in a cannabis plant, the plant will not be able to make the strong stems it needs to support big flowers. Not only that, but it will not be able to make the chlorophyll it needs to properly make sugars and proteins for photosynthesis.
This causes a plant to be weak, and not have the ability to support itself. Weak stems can be a sign of nitrogen deficiency, but it can also be a sign of many other cannabis plant problems. Proper diagnosis is key to successful treatment. Ask for help here if you need it!
How to Fix Nitrogen Deficiency in a Cannabis Plant
To fix a nitrogen deficiency in a cannabis plant, there are two things you should do:
1: Increase the amount of nitrogen in the medium, by increase the amount of nutrients in your feed
2: Ensure the pH of the medium is balance to the correct levels.
Fixing Nitrogen Deficiency in Soil
When you grow cannabis in soil, you may not need to feed your plants for the first couple of weeks after transplanting them. This is because there are plenty of nutrients available in the soil.
As time passes, and the plant gets bigger, you will need to add plant food to the medium to give the plant to food it needs to grow.
If you haven’t fed your plants yet, and the deficiency is just starting, now is a good time to introduce nutrients to the plant.
On the other hand, if you have been feeding you plants, increase the dosage of grow foods a little and continue to feed at a higher dose for a few feeds.
Monitor the plant for any changes, and adjust accordingly. If it continues to turn yellow, raise the dosage, if the plant starts to turn dark green, reduce the dosage.
The ideal pH level for cannabis plants growing in soil is between:
6.5 and 7.5
Fixing Nitrogen Deficiency in Hydroponics
Fixing nitrogen deficiency in hydroponics is relatively easy. All you have to do is increase the EC of your feed a little. Because salt based nutrients are readily available to the plant, increasing the EC just a little can see the plant improve within 24 hours.
Always be careful not to over do it, gradual changes are key to not causing another issue. It is easy to over feed a cannabis plant, so take it lightly when increasing the EC.
Along with the EC, your plant may not be able to get the nitrogen that is available to it if the pH of the medium of not in the correct range. Ensure your pH is on point too! Otherwise it doesn’t matter how much nitrogen you feed the plant, it won’t be able to eat it.
Optimal pH levels for hydroponics are between:
5.8 and 6.2
Preventing Nitrogen Deficiency in a Cannabis Plant
To prevent a nitrogen deficiency in a cannabis plant, you should monitor you plant for changes daily. If you see any of the symptoms mentioned in this post starting to arise, then you should act right away.
If your plant starts to turn pale, or yellow, especially on the lower portion of the plant, then you should increase your feed a little to prevent a deficiency occurring.
The best way you can prevent problems with your cannabis plant, is by getting help from experienced cannabis growers. In our forum, we have a section for cannabis grow diaries. If you are a new grower, start a grow diary, and you can be helped step by step through your grow. This is the best way to prevent problems from arising for new growers!
Never rush into treating a cannabis plant problem if you do not know what the cause is! You can find all the help you need in our cannabis growers forum just sign up! It is a good idea to get a second opinion before treating you plants, just to make sure your doing the right things.
Thanks for reading! Happy Growing