Nitrogen Deficiency in Marijuana Plants

One of the common nutrient deficiencies that most growers deal with is Nitrogen deficiency. Whether you are a newbie grower or a veteran, diagnosing the lack of macronutrients like nitrogen, potassium, and phosphorus is never an easy task. However, you need to quickly solve this problem for the well-being of your marijuana plants. Before supplementing more plant nutrients, you should stop and take the time to identify the actual problem.

Most growers do more harm to their plants by blindly adding products to their pot plants without determining the problem at hand.

This article will help you get all the information that you need about nitrogen deficiency in cannabis plants and how to deal with the problem.

What is Nitrogen Deficiency in Cannabis Plants?

cannabis nitrogen deficiency

This is a deficiency where cannabis plants show that they do not have adequate Nitrogen needed to grow. To solve this problem, your marijuana plant will suck nitrogen out of the older parts or lower leaves of the plant. As a result, the leaves will crisp up and change color. This should not be a cause for alarm because Nitrogen Deficiency is one of the common nutrient deficiencies that many indoor cannabis growers deal with. Furthermore, the remedy is also straight forward and simple.

The Importance of Nitrogen in Marijuana Plants

cannabis nitrogen deficiency 2

For marijuana plants, Nitrogen is one of the major 3 essential elements apart from Phosphorus and Potassium. The usage of Nitrogen is present mostly during the Vegetation phase because it is an important component of chlorophyll, necessary for photosynthesis in plants. Furthermore, nitrogen is a crucial component of Amino Acids, which are the building blocks of proteins and this makes this nutrient necessary for pot plants to grow. Nitrogen is also a crucial component of nucleic acids such as DNA and RNA that plants require for successful growth and reproduction.

Because the use of Nitrogen in pot plants is mainly meant for tasks in the vegetative state, the plants will stop absorbing Nitrogen when the production of flowers begins. Therefore, as a grower, you must ensure that your plant does not get nitrogen deficiency in the early flowering stages. Here is how nitrogen is used in cannabis plants.

Read next: How To Identify And Treat Magnesium Deficiency 

Vegetation State

At the vegetation stage, pot plants utilize Nitrogen for the following:

  • Production of enzymes
  • Production of new plant cells
  • Necessary for the production of chlorophyll the green pigment required for photosynthesis
  • Responsible for growth of stem and leaves

Flowering Stage

At this stage, there is no uptake or very low uptake of Nitrogen from the roots by the cannabis plants. However, during the flowering stage, Nitrogen is still necessary for the following:

  • The growth of small leaves close to the flowers
  • The growth of top leaves where access to light is not adequate

Signs of Nitrogen Deficiency in Cannabis Plants

Signs of Nitrogen Deficiency in Cannabis Plants

As you can see, nitrogen is extremely important to your marijuana plants and a deficiency can be extremely damaging to the plants. Fortunately, detecting nitrogen deficiency in cannabis plants is very easy, if you know what you are looking for. Just like most ways of detecting nutrient deficiencies in cannabis, the leaves is where you should be looking at if you suspect a nitrogen deficiency.

One of the key signs of lack of nitrogen in your weed plants is the yellowing of leaves. The leaves usually start to yellow from the tips and move inward until the whole leaf is yellow. The lower and older leaves of your plant will become yellow, wilt, and then drop off. This happens because the younger leaves that are higher up the plant will start taking up nitrogen from the older, lower leaves.

Cannabis plants prioritize the higher leaves because they receive more light and greatly contribute towards photosynthesis. The symptoms of deficiency will start at the bottom of the cannabis plant and move to the top since nitrogen is a mobile nutrient. If this does not happen, then it means that you are dealing with a different nutrient deficiency or light burn.

Signs of Nitrogen Deficiency in Cannabis 2

Signs of Nitrogen Deficiency in Cannabis:

  • Red stems
  • Leaves turn pale green
  • Yellowing of the older and lower leaves
  • Browning of the leaves
  • Yellowing of the veins on the marijuana leaf
  • Leaves start drooping
  • Wilting Leaves will break off
  • A slow growth rate during the vegetative stage

The best solution for nitrogen deficiency is to provide your cannabis plants with a well-balanced nutrient product. There are many formulas available today that can offer a range of important nutrients to your plants. Cannabis growers must ensure that they keep the nitrogen levels healthy throughout the important vegetative phase.

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The Causes of Nitrogen Deficiency in Weed Plants

Nitrogen Deficiency in Cannabis Plants

Unhealthy soil is one of the major causes Nitrogen deficiency in weed plants. If you add organic matter that has a high concentration of carbon to your soil, then nitrogen in the soil will be broken down to carbon by the soil organisms. Your cannabis plants will then absorb less nitrogen from the growth medium because it is not bio-available. This can also happen when there is excess sand and organic matter is not well decomposed or too much rain.

In some cases, there may not be enough biology in your soil to transform nitrogen in inorganic materials or the atmosphere into forms that can be utilized by cannabis plants. Therefore, cannabis growers must be cautious about what they do to the soil medium. If the soil or growing medium is treated poorly, cannabis plants will suffer from a deficiency of nitrogen and other nutrients.

Nitrogen deficiency in weed crops can also be caused by waterlogging. When there is excess water in the soil, bacteria will convert nitrate into nitrogen gas, which will be lost to the atmosphere. If you also use chlorinated water on your plants, you will end up converting nitrate into nitrogen gas and deprive your cannabis plants of the right amounts of nitrogen they require. Furthermore, in high concentrations, chloride can be toxic to weed plants and should be avoided at all costs.

Other elements in the soil like zinc, manganese, and potassium may affect the concentration of nitrogen available in the soil. The pH levels of the soil or grow medium may not be correct and the cannabis plants will not absorb nitrogen even if the supply is adequate. There are many causes of nitrogen lacking in your cannabis plants and you need to measure the nitrogen levels and take the necessary steps to quickly rectify this problem.

Read next: Best Soil For Weed

Fixing Nitrogen Deficiency in Marijuana Leaves

Fixing Nitrogen Deficiency in Marijuana Leaves

When solving nitrogen deficiency on weed plants, your action will be different in the vegetative and flowering stages. This is why we will cover the different stages by diving them into three parts, the vegetative phase, early flowering, and late flowering stages.

  • Solving Nitrogen Deficiency During the Vegetative Stage

Marijuana plants take up more nitrogen during the vegetative stage. The plant uses nitrogen for growing new sections and its needs for nitrogen will keep growing. If the cannabis plant does not get adequate nitrogen from the growing medium, it will start taking up nitrogen from the lower parts of the plant that receive less light. This nitrogen will be used in the growth of the higher plant sections.

Therefore, growers must ensure that their plants do not have nitrogen deficiency during the vegetative period. However, fixing this deficiency is easy. All you need to do is increase the amount of nitrogen in your next mix and maintain a pH of 6.2 to 6.8 and the spreading of symptoms on your cannabis plant will gradually stop. However, just like other deficiencies, the most affected leaves never recover.

Some Nutrients For Vegetative Stage:

  • Treating Nitrogen Deficiency During the Early Flowering Stage

After the cannabis plant has completed its vegetative growth, it will naturally reduce or even stop absorbing nitrogen from the growth medium. This makes nitrogen problems more serious because you may lose a significant quantity of leaf mass. If you discover nitrogen deficiency early, you should definitely act fast to save your cannabis plants.

You can solve this problem by spraying the cannabis plants with a water and nitrogen mixture for about 15 minutes before lights out. Based on where your plants are in the flowering phase, they may absorb nitrogen through the leaves.

  • Fixing With Nitrogen Deficiency During the End of The Flowering Stage

During the last 2 or 3 weeks of the flowering stage, when flushing your cannabis plants, you want this nitrogen deficiency to persist. If you do not force your plants into a deficiency, the buds will weigh much more, but will not have a good taste and may sparkle a little. As a result, you will be losing a lot with regards to the quality of your buds and the taste of your final harvest.

The Only Time You Should Have a Nitrogen Deficiency in Cannabis Plants

Nitrogen Deficiency in Cannabis Plants 2

There is a time during the cultivation of cannabis plants that you will actually desire a nitrogen deficiency. The only time you will want this is at the end of the flowering stage. Based on the strain of cannabis, you want the leaves to start turning yellow at about 8 to 10 weeks of flowering. This is a phenomenon that is specific to cultivating weed because it has everything to do with the final product, the buds.

Chlorophyll is the crucial pigment that helps in light absorption. During the end of the flowering process in cannabis, you will have to kill the plants for you to harvest them. The problem is that chlorophyll contains a smell similar to dry grass or hay that you can taste when smoking the resultant product.  The best way to eliminate this taste and smell is by flushing out chlorophyll from the plants.

Cannabis growers usually start by watering their plants with very small amounts of nutrients to trigger a nitrogen deficiency in marijuana plants. This is apparent when you check out pictures of cannabis plants that are ready for harvest. You will mostly notice large buds and most of the plant leaves have a bright yellow color. You can also get rid of excess chlorophyll during the drying stage by leaving the plants in complete darkness for several days to hasten the chlorophyll dissipation from leaves.

Read next:  Cannabis Heat Stress- How to Prevent & Treat

The Bottom Line

Nitrogen deficiency can have dire consequences on your marijuana crops. This is why you should inspect your plants for signs of nitrogen deficiency and consult experienced growers for advice. You should never rush to treat the problem if you are not sure of its cause. With the right remedies, your plants will get adequate nitrogen to support its growth and you will end up with green, healthy, and sweet-smelling cannabis crops that will produce the highest, quality yields possible.

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Bowden draws from over a decade of home growing experience as well as consulting for small-scale and hobbyist-level growers. He has written hundreds of articles, thought pieces, and tutorials about growing cannabis at home

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