Essential Nutrients to Grow Marijuana: A Beginner's Guide

Cherie Crocker | June 24, 2022

Nutrients are necessary to grow marijuana indoors or outdoors. When left on its own, a cannabis plant can grow fine as long as it is planted on good soil and provided with sufficient water and light. However, it needs essential nutrients to grow healthy and produce dense buds. 

What are Cannabis Nutrients?

Cannabis does not only need a grow light and sufficient water. It also needs nutrients or substances essential for its growth and sustenance. High-quality marijuana, with potent THC, CBD, and other cannabinoids, requires more nutrients to thrive, grow, and produce abundant yields. 

Nutrients for outdoor cannabis plants often come in powdered form. The growers usually add these fertilizers to the soil before transplanting the cannabis plants outdoors. The fertilizer will give the plants all the nutrients needed until harvest time. If the cannabis plants still require more nutrients, the cultivators add more fertilizer to the top soil.

Indoor cannabis fertilizer usually comes in liquid form. The growers mix the liquid with water and use the mixture to water the plants. Using liquid fertilizers consumes more time because you have to measure them, mix them with water, and use them on the plants at least once or twice a week. 

Using liquid indoor growing fertilizer for outdoor plants is not recommended because the synthetic mineral salts in the fertilizer tend to damage outdoor soil bacteria. 

What Kind of Nutrients Does Cannabis Need?

There are three nutrients that marijuana needs in large quantities for maximum yield. These primary nutrients or micronutrients are:

  • Nitrogen (N)
  • Phosphorus (P)
  • Potassium (K)

These three are the main content of fertilizer products and are expressed in terms of NPK ratio. The ratio value represents the concentration of each nutrient in the mix.

However, cannabis also needs more than these three nutrients to thrive. It will also need smaller quantities of other nutrients vital to its growth. These substances, called micronutrients, include:

  • Calcium (Ca)
  • Magnesium (Ma)
  • Sulfur (S)

Marijuana needs various amounts of these essential nutrients throughout its different growth stages. In its vegetative growth phase, it requires more nitrogen, but in its flowering phase, it requires more potassium and phosphorus. 

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As mentioned earlier, marijuana needs more nitrogen to develop in the vegetative stage of its life cycle. It is necessary to produce chlorophyll, an essential compound required for photosynthesis. Without it, the plant cannot grow because it cannot convert sunlight into usable energy.

Nitrogen also forms part of the amino acids that make up proteins, a necessary compound essential for the structural integrity of the plant. In addition, it forms part of ATP, a molecule that stores and releases energy, and nucleic acid, a component of the plant's DNA. Without it, the plant will be frail.


Phosphorus is an essential nutrient required to produce dense and healthy buds. Its main role is to ensure that the plant has the ability to absorb all other nutrients essential to build the different plant structures, from the roots to the flowers. If the plant lacks phosphorous, it will likely have underdeveloped parts. A purple hue in the leaf veins is an early sign of phosphorous deficiency. 


Potassium helps regulate various systems that ensure the plant's healthy development. For instance, it plays a huge role in regulating salt and water concentrations within the plant. It does this by controlling the inflow and outflow of H2O, CO2, and oxygen through the pores of the leaves. 

Potassium also plays a vital role in ATP production, the powerhouse of the cell that stores energy in the form of glucose. As the plant grows, it utilizes glucose in the ATP for energy. If the plant lacks potassium, it will eventually starve to death because it cannot regulate the exchange of H20, CO2, and oxygen. 


Calcium is necessary for keeping the cell wall structure intact and helps regulate salinity. Without this necessary element, the plant will not continue to grow and develop. Hence, the leaves begin to wither, and the plant eventually dies.


Magnesium is vital in photosynthesis because it is a necessary molecule in chlorophyll. Without chlorophyll, the plant will not be able to produce glucose. Even if the plant receives sufficient sunlight, it will not be able to convert it to energy. This element is necessary for the production and metabolizing of glucose. The plant can grow and mature into a healthy plant with sufficient amounts of this element.


Sulfur is essential in forming chlorophyll and producing proteins and enzymes that protect against diseases. Although the plant only needs a small amount of this element, it will show severe signs of the deficiency without it. The most common symptom of deficiency is the presence of yellowing in the midsection of the leaves.

The nutrients mentioned above are the most crucial. However, the plant needs various other micronutrients to help it grow and reach its maximum potential. These include iron, chlorine, boron, copper, and zinc. 

Bottom Line

Cannabis plants need base nutrients to grow healthy. These nutrients are listed on the labels of fertilizer products. You should apply them to your plants throughout their growing phase. However, not all fertilizers are made the same. If you want quality nutrients for your garden, check out Cannabis Grow Supplies - Base Nutrients

cannabis growth

How to Use Cannabis Nutrients

Cannabis fertilizers will indicate the ratio of Nitrogen, Potassium, and Potassium in each bag or bottle. These are the three main nutrients found in fertilizers. For instance, a certain product may indicate a 3-1-1 N-P-K ratio. It means that it contains three times more nitrogen than phosphorous and potassium. 

Cannabis plants have their requirement for each nutrient, depending on their development stage. Hence, the purpose of the NPK ratio is to provide you with a clear idea of what stage of development it is designed for. However, there is not one ideal NPK ratio for each development stage. Each brand would be coming up with different nutrient percentages based on their research.

Cannabis growing requires attention to detail because the plant needs different amounts of nutrients as it transitions into different stages of development. Fertilizers with higher nitrogen and a lower phosphorus and potassium content are intended for vegetative states. In comparison, fertilizers with lower nitrogen and a higher phosphorus and potassium content are designed for the flowering stage. 

When you shop for fertilizers, you will notice that they are often divided into "grow" and "bloom" solutions. The "grow" products contain higher nitrogen, while the "bloom" products contain lower nitrogen. You can easily identify which fertilizer to use using these general descriptions.

Whenever you fertilize your crops, you have to perform flushing during the last week before the harvest. Use pure water to remove the nutrient buildup in the buds. 

Visit Cannabis Grow Supplies - Nutrient Kits for your plant nutrition needs. 

How to Use Liquid Nutrients

You will use liquid nutrients when you grow cannabis in an indoor garden. These nutrients work for hydroponics, soil, and other grow media. You can use drip lines and hoses for more efficient nutrient delivery. Please note that the roots easily absorb nutrients in liquid form. Hence, they act fast and can cause damage in large quantities. 

You will need a dedicated container to mix the nutrients with water. Be sure to follow the instructions on the product label. You have to add the correct ratio of liquid nutrients into a given amount of water. 

You do not have to add liquid nutrients when you water your plants. Use them only on a set schedule. Remember that adding too many nutrients will damage your plants. Always monitor how much nutrients you give your plants. It is best to start with a lower solution to see how the plants react. If you put too little, the plants will not grow large enough. Simply add more during the next fertilizing schedule. 

Related Topic: Basic List of Cannabis Growing Supplies for Beginners

Nutrients For the Vegetative Stage

The vegetative stage of cannabis is when the plant grows from a seedling to a mature plant. It takes around 3-12 weeks and will require significant water, light, and nutrients. It is essential to supply it with these elements to ensure its healthy growth. If you have an indoor garden, use ample lighting from a grow light. 

Nitrogen helps regulate protein production and the development of leaves and stems. During the growth phase, marijuana requires high nitrogen levels. When there is nitrogen deficiency, the leaves become yellow, and the plant becomes light green. If the foliage turns very dark, it may signify overfertilization. 

Nutrients For the Flowering Stage 

The flowering stage is when the marijuana plants begin to grow buds or flowers. During this phase, the plants need more phosphorus and potassium and less nitrogen. Hence, you should use a fertilizer that is designed primarily for blooming. Make sure that the fertilizer you buy has lower levels of nitrogen.

When you fertilize the plants properly during the blooming stage, you will gather healthy and dense buds, which is definitely what you should aspire to achieve. You may also use supplements to increase the absorption of the fertilizers to produce better yields. Supplements are designed to promote the production of cannabinoids and terpenes and increase the plant's immunity against diseases. 

Using Organic Nutrients

Organic fertilizers from organic sources, including vegetable and animal waste, can do wonders for cannabis growing. The organic nutrients from these sources contain beneficial substances for the plant and the soil. They are commonly in powder form and are used for outdoor growing.

Organic nutrients and fertilizers are not as harsh as liquid nutrients. They are not immediately absorbed by the roots and are beneficial to the organisms found in the soil. You can buy these fertilizers from local sources without spending a fortune. Once you use them correctly, you only have to water the plants regularly because the soil already contains all the necessary nutrients that the plants need. 

Benefits of Organic Fertilizers

Organic fertilizers improve the overall quality of the soil, which will eventually benefit the quality of the cannabis plants. Some of the other benefits include the following:

  • They have a lower chance of nutrient run-off
  • They improve the water retention and airflow in the soil
  • They have a slow release of nutrients and will not readily damage the plants
  • They are a renewable and sustainable source of nutrients
  • They help diversify organic life in the soil

If you want an environmental-friendly fertilizer, you may want to consider going organic. As you repeat the use of organic fertilizers, you may find that the soil continues to improve year after year. Depending on the fertilizer's nutrients, you may grow plants with a better terpene profile.

Disadvantages of Organic Fertilizers

Using organic fertilizers can be complicated. Not all people have access to good quality organics. Some growers find that it may lead to nutrient deficiencies. The nutrients are less soluble and may not provide enough to sustain the plant's growth. Some of the other disadvantages include the following: 

  • It takes time for the nutrients to be absorbed
  • The soil needs to have microorganisms to break the nutrients down for the plants
  • Organics may attract pests and insects

Bottom Line

Using organics is a great way to grow marijuana. Going organic allows you to be in tune with nature, help the environment, and provide a renewable and sustainable source of nutrients for your plants. However, you must ensure that your fertilizers contain all the essentials your plants need. For quality organics, visit Cannabis Grow Supplies - Organic Nutrients

Frequently Asked Questions

When Should I Start Using Nutrients For Cannabis?

Some fertilizer brands suggest using fertilizers during the seedling stage, around one week after the seed germinates. This recommendation is fine, but you may also start once your seedlings have grown two to three leaves. Always be careful with seedlings because they only need a little nutrition. 

Sooner or later, your plants will need a nutritional boost depending on the growing medium. Some soil mixes come with nutrients that are good for the first three to four weeks. Hence, you should avoid adding more fertilizers until the three to four weeks are up. Read what is on your mix carefully before adding additional nutrients. 

Do I Need to Add Nutrients Every Time I Water The Plants?

It depends on the product you are using. Some are designed to be applied once every week only. Others are designed to be applied every time you water. Follow the instructions provided by your fertilizer brand to avoid causing a nutrient burn. Monitor your plant's nutrient intake and follow a schedule to avoid excesses or deficiencies.

How Will I Know When to Switch To a Flowering Fertilizer?

The first sign that the plant has entered the flowering stage is when the pistils start to develop. You can calculate when this will happen by researching the cannabis strain you planted. You may switch to bloom nutrients when the flowering stage has begun. You may also base the switch on the plant's age or height. 

How Frequently Should I Fertilize The Plants?

Read the label on your fertilizer. Some are designed to be applied every time you water. Others should be applied once a week. You may apply supplements once every month or within specific weeks. Always read the instructions on your fertilizer brand and follow the recommended schedule to achieve the best results. 

How Do I Know When to Stop Giving Nutrients?

When the trichomes are milky or amber in color, it is time to harvest your buds. You should stop giving nutrients during the last two weeks or the last week of the flowering stage. After stopping, you should water the plants with pure water only to flush the buildup of nutrients on the buds. The buildup of nutrients causes the chemical flavor in the flowers. You can minimize this by performing a flush. 

What Is a Nutrient Burn?

A nutrient burn is a result of overfeeding the plants with nutrients. The excessive nutrient buildup will cause the plants to develop dark green leaves with tips that bend upwards. This can be remedied by flushing the roots with water for at least a week before reintroducing the fertilizer. 

Are Organic Fertilizers Better Than Chemical Fertilizers?

Organic nutrients are encouraged because they are absorbed much slower, thus reducing the chances of a nutrient burn. They also benefit the soil by promoting a healthy ecosystem for microorganisms. However, chemical fertilizers also have their pros. They are easily absorbed by the plants and provide nutrient efficiency. Nevertheless, you have to weigh the pros and cons. The decision is up to you. 

Last Words

There are many ways to grow marijuana. You can follow the traditional or more modern ways, like hydroponics and aeroponics. You can use indoor growing systems if you do not have enough outdoor land. Whatever method you choose, you need essential nutrients to ensure a good yield. Follow the recommendations stated above, and you are on your way to producing high-quality marijuana for personal or commercial use.