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Understanding Nutrients and Fertilizers For Marijuana Plants

Like all plants, cannabis needs nutrients and fertilizers to stimulate growth. However, not everyone understands all of these fertilizers well.

You may be a beginner in growing cannabis and not sure what fertilizer is good for your plants. If so, immediately read the information below, they will be extremely useful for your tree planting work.

This article will help you better understand some fertilizers and nutrients that help cannabis plants grow at their best. At the same time, we will also specifically indicate the suitability of each type of fertilizer in the growth stages of the plant.

Let’s get right into the details!

What Are Cannabis Nutrients?

Cannabis nutrients or fertilizers are nutrients that help stimulate plant growth. Many different types of nutrients are suitable for each growing medium and stage of the cannabis plant.

For example, it is common for outdoor gardens to choose powdered nutrients and mix them directly into the soil before growing the baby cannabis plants. Even this amount of nutrients can be enough for the real growth of the plant without additional fertilization.

As for indoor gardens, some experts often choose liquid nutrients, mix them with water and fertilize the plants during their growth stages.

Types Of Fertilizers

types of fertilizers
Types Of Fertilizers

Currently, there are many types of fertilizers that you can use to add nutrients to the cannabis plant. To choose the right fertilizer for plants, you first need to learn basic information about fertilizers.

Chemical Fertilizer

Chemical fertilizers are synthetic fertilizers made from chemicals to provide nutrients to plants. Normally, you will use chemical fertilizers with the right ratio of NPK, macronutrients, and micronutrients for synthesis.

Chemical nutrients are usually readily available so the plant can absorb them immediately. Therefore, chemical fertilizers help save planting time and still help plants grow and develop well.

However, when applying chemical fertilizers, You need to follow the instructions for use and apply the right rate to avoid the plants being over-fertilized, leading to slow flowering or death.

Organic Fertilizer

Organic fertilizer is a natural fertilizer produced from mineral sources (limestone), plant waste (compost or seaweed extract), and animal wastes…

Organic fertilizers are generally safe and stimulate good plant growth. However, the bone meal needs to undergo composting and processing for plants to absorb the best organic compounds such as bird droppings.

We can compost these organic fertilizers ourselves or can buy them at stores.

Difference Between Organic Fertilizer vs Chemical Fertilizer

micronutrients for cannabis plants
Micronutrients For Cannabis Plants

Organic fertilizers and chemical fertilizers are both good for the growth of cannabis plants. Therefore, you can consider and make a decision to choose the right fertilizer for your cannabis garden.

Chemical fertilizers have the advantage of being readily available and easily absorbed by plants. However, if you are not careful, you can fertilize with too much fertilizer that the plant cannot drink, even harming the plant.

Chemical fertilizers are more environmentally friendly. The downside is that they may take you more time to compost and process, but they are great for plants and soil. In particular, applying organic fertilizer with a large amount will still not harm the plant.

What Are Macronutrients And Micronutrients For Cannabis Plants?

Macronutrients and micronutrients are concepts you need to know when learning about nutrients and fertilizers for cannabis plants.

Plants and cannabis typically derive their micro and macronutrients from the soil, water, and air. Some of the basic elements in micro and macronutrients include carbon ©, Oxygen (O), and Hydrogen (H).

To provide these nutrients to the cannabis plant best, you should keep the air in the growing room always clear and fresh so that the plants can receive this natural oxygen and carbon. Besides, it is better to install a carbon filter and water filter system for the garden.

What Is NPK?

What is NPK
What is NPK?

NPK is a major macronutrient that plays an important role in plant growth. NPK is an abbreviation for a mixture of chemicals, including Nitrogen (N), Phosphorus (P), and Potassium (K).

They are essential nutrients that help stimulate the strong and effective growth of the cannabis plant.

Secondary Macronutrient And Micronutrient For Cannabis

Secondary macronutrients include calcium, magnesium, and sulfur. These substances support the macronutrients that contribute to the good growth of the cannabis plant.

The other macronutrients or micronutrients include manganese, boron, iron, sulfur, molybdenum, copper, and zinc, which are commonly found in most common fertilizers today. However, because they account for a very small amount compared to other macronutrients, they are called micronutrients.

How To Read Fertilizer Numbers

Usually, the packaging of cannabis nutrients will contain a lot of parameters, which can make you dizzy because you do not understand anything. Do not worry! We’ll teach you how to read the numbers on these nutrients so you can get a basic understanding of them.

First, in most organic fertilizers, NPK is indicated, representing the main nutrients present in that fertilizer. At the same time, they have different numbers showing the percentage of each element in the fertilizer mixture.

For example, the designation NPK 5-12-15 on the package may indicate that the fertilizer contains 5% nitrogen, 12% phosphorus, and 15% potassium.

How To Use And Mix Cannabis Nutrients?

How To Use And Mix Cannabis Nutrients
How To Use And Mix Cannabis Nutrients ?

During each stage of growth, cannabis will need these nutrients in varying amounts. For example, plant growth requires more nitrogen, while flowering requires more potassium and phosphorus. Therefore, you need to pay attention to choose the right fertilizer.

You can buy ready-made fertilizers at the store to use. With a powdered fertilizer, you can mix it with the soil before planting the seedlings. As for liquid fertilizer, mix it with water and water the plants.

Besides, to mix fertilizer, please note what the needs of the cannabis plant are? For example, at the growing stage, mix fertilizer with a higher percentage of Nitrogen. On the contrary, when the plant is flowering, fertilizer should be mixed with a higher ratio of potassium and phosphorus to be good for flower development and flower quality when harvested.

What Is The Best Type Of Weed Fertilizer?

To help you better understand the most commonly used nutrients and fertilizers, we’ve rounded up some of the best fertilizers for cannabis plants. Below, you can refer to them.

NPK Fertilizer

The first is NPK fertilizer – the best synthetic chemical fertilizer for cannabis plants. Farmers can buy this fertilizer easily at stores. Alternatively, for powdered NPK fertilizers, you can also mix them into the soil, which is known as booster fertilization.

In particular, how to use NPK fertilizer to fertilize plants is also very simple. You can mix it with water and water the plants.

However, NPK fertilizers also have many types with different ratios of Nitrogen, Potassium, and Phosphorus. You should consider the soil characteristics and the growing stage of the cannabis to choose the NPK fertilizer with the most suitable ratio.

Worm Castings

worm castings organic
Worm Castings Organic

Worm casting or earthworm is a form of organic matter made from the waste of earthworms. People make worm manure by allowing this organism to live and eat compost. When they do, they produce waste with optimal nutrient content for the soil.

Worm manure helps to provide additional nutrients to the plants. So, this type is a very good chemical fertilizer for cannabis because it allows the soil to aerate, drains well, increases water retention for plants, and enriches the soil with nutrients.

Good Bacteria And Fungi

After processing or fermentation, good bacteria and fungi can become good nutrient compounds for plants, especially cannabis plants. They are an organic compound that supports the growth and development of the cannabis plant. You can buy this fertilizer at stores and use it easily.

Forest Humus

Forest Humus
Forest Humus

Forest humus is an organic compound that is completely decomposed by elements belonging to the forest layer. Usually, it takes about hundreds to thousands of years for these organics to become humus in a natural way.

Forest humus is very good for plants, especially the growth of cannabis. You can use forest humus as chemical fertilizer and apply it directly to the soil.

This organic substance is rich in nutrients, safe, and especially environmentally friendly.

Fish Meal

fish meal
Fish Meal

Fishmeal is a nutritional supplement made from fish bones and organs. You can use it mainly as food for some animals but more commonly as fertilizer.

Fishmeal processing is very simple, and they are a by-product of the aquaculture and seafood processing industry. It is mainly made from leftover products, so it is quite economical.

Fishmeal is very cheap, but they are quite high in nutrients. Therefore, this is a very good organic fertilizer for cannabis plants that you should choose.

With these nutrients, you can mix them in water and water your plants. In addition, you can also mix fishmeal into the soil as a very good fertilizer for the earth.

Blood Meal

Blood Meal is an inert, dry powder made from blood. They are high in nitrogen and are a rich organic fertilizer for cannabis plants.

You can use this fertilizer during the growth phase of the plant. It will help your cannabis plant to grow and thrive.

Bat Guano

bat guano
Bat Guano

Bat Guano is the accumulated waste of seabirds and bats. This organic fertilizer contains very high levels of nitrogen, potassium, and phosphorus. Therefore, they can replace chemical fertilizers NPK.

Bat Guano is a natural chemical fertilizer with a reasonable cost, so many people use them in farming. In particular, professional cannabis growers love this fertilizer.

Because they are not only nutritious, safe, and easy to buy, but they are also very good for the growth of the cannabis plant. You can use this fertilizer during the growth phase of the plant. They will surprise you with the effect after using the cannabis plant.

In particular, this fertilizer is very safe and environmentally friendly, so everyone should actively use them.

Compost Tea

compost tea
Compost Tea

The brewed tea is an organic fertilizer produced from plant waste. You should compost the peels of fruits, roots of vegetables… to form this chemical fertilizer.

After the composting process, these plants decompose and create organic nutrients that are good for the soil and plant growth. Then you can bring them to fertilize your cannabis plants.

Although it takes time to process, brewed tea has a fairly high nutrient content and is great for the cannabis plant. More importantly, this fertilizer is very economical and good for the environment.



Biochar is a type of coal produced through pyrolysis without oxygen. This type of coal is very good for soil improvement, making the soil richer in nutrients.

Biochar is rich in carbon and can remain in the soil for thousands of years. They aid in increasing the fertility of crops such as cannabis. At the same time, this fertilizer also has the ability to support pests on leaves.

Cannabis Fertilizers And Supplements

Another problem that many people often confuse is that supplements are also fertilizers. However, the reality of supplements and fertilizers is completely different.

You need to be able to distinguish between fertilizers and supplements for cannabis plants. Unlike fertilizers, additives are commonly used substances that improve the physical characteristics of the soil to help plants grow or increase crop yields.

Supplements are usually very low in NPK and contain several micronutrients. Specifically, compost, humic acids, probiotics, fulvic acids, and wetting agents are some examples of supplements.

During the growing process, you should apply the main fertilizer (with high NPK content) during the growing and flowering stages. Besides, you should use more supplements to create bounce for the plants and increase the richness of the soil.

The combination of using both fertilizers and supplements in the right way will help your plants grow well and produce the highest yield.

Nutrients For Seedlings

nutrients for seedlings
Nutrients For Seedlings

If your soil is rich in nutrients during the seedling stage, you don’t need to add more fertilizer. Because at this time, the plant will slowly absorb nutrients from the soil.

Note, you should add organic nutrients to the soil before planting seedlings. The types of nutrients you can use to mix in the ground are forest humus, worm manure, and processed fish meal.

In short, you do not need to apply too much fertilizer in the young plant stage if you have prepared nutrient-rich soil. If you want to fertilize during this period, it is best to use a processed organic fertilizer.

Nutrients For Veg Stage

nutrients for veg stage
Nutrients For Veg Stage

The vegetative phase is an important stage where you need to provide additional nutrients to the cannabis plant. This phase usually lasts about 4-12 weeks.

Supplementing the cannabis plant with nutrients during the vegetative phase is essential. Because, at this stage, the plant has almost absorbed all the nutrients available in the soil. At that time, to stimulate the plant to grow fast and healthy, you should add nutrients to the plant.

Note, you should choose the right type of nutrients that can support your garden to grow well and give a high yield.

During the vegetative phase, you need to provide the cannabis plant with a large amount of nitrogen. Therefore, the best fertilizer for this period is a fertilizer with a high N ratio. For example, the NPK fertilizer rate should be chosen as NPK (10-5-9).

However, you should observe the plant and fertilize it according to the prescribed rate stated on the package. Because if you over-fertilize, your cannabis leaves can wilt, turn yellow, and even die.

Nutrients During The Flowering Stage

nutrients during flowering stage
Nutrients During Flowering Stage

The flowering period is the second most important period for people to pay attention to adding nutrients to the cannabis plant. Fertilizing at this stage helps to stimulate flower growth and improve the quality of the finished product at harvest.

Unlike the growth phase, the cannabis plant will absorb more potassium and phosphorus during the flowering period. Therefore, at this stage, to stimulate flower development and increase the quality of the finished product at harvest, a fertilizer with a higher ratio of K and P should be selected.

For example, people can choose fertilizers with NPK ratios of 6-10-10, respectively.

During the flowering phase, people can incorporate fertilizers and supplements into the cannabis plant. Of course, you should only fertilize at the right rate for healthy plant growth and better quality and flavorful flowers.

FAQs – Nutrients and Fertilizers For Cannabis

People often have a lot of questions related to the topic of nutrients and fertilizers for cannabis plants. As a beginner, we believe you will also wonder about these issues.

Therefore, we have compiled some frequently asked questions about nutrition for cannabis plants that you can refer to below.

When should I start feeding my plants with nutrients?

You should start providing nutrients to the plants as soon as they start to grow about 2-3 sets of leaves. Note that you should choose a fertilizer suitable for the stage of the plant.

In addition, the time to fertilize the cannabis plant will also depend on the soil the plant is grown in.

For example, if your soil is good and rich in nutrients, you can apply it later. On the contrary, in case the ground is low in nutrients, you need to fertilize early to supplement the plants.

Should I use nutrients every time I water?

You can use nutrients each time you water the plants. However, you need to pay attention to the directions for use printed on the packaging of that nutrient.

Because there are certain nutrients, you can use multiple times per week that you can use each time you water your cannabis.

On the other hand, some nutrients should only be used once a week, so you should use them when watering, and on different days of the week, you should only water the plants.

When to switch to flowering nutrients?

You should switch to a flowering nutrient when you notice your cannabis plants showing signs of flowering (pistil growth). Specifically, if you want the plant to flower early, you can apply flowering nutrients from the 4th or 5th week of the plant’s growth period.

Conversely, if you want to prolong the plant’s growth, you can switch to a later flowering nutrient regime, waiting for the plant to grow large enough in the growing medium.

In addition, to stimulate flowering quickly, you can change the light and lighting cycle for the plant (suitable for growing cannabis indoors).

How often should I give my plants nutrients?

The regular supply of nutrients to the plant will depend on the type of fertilizer you choose. Some recommend that you use it every time you water; others recommend once a week.

In addition, some other fertilizers only need to be used once a month.

When should I stop giving my plant nutrients?

You should stop providing nutrients to the plant two weeks before the plant begins to flower. Instead, water regularly to wash away the plants and reduce the taste of “chemicals” for flowers when harvested.

Stopping fertilizing at this point helps flowers have a more natural flavor, curl, and better color.

How to prepare cannabis nutrients?

You can prepare nutrients for cannabis by purchasing pre-made varieties or mixing the nutrients yourself. However, be careful to choose the right nutrients for the growth stage of the plant.

Because only the right fertilizer can stimulate the growth of cannabis and give you a good effect when harvesting.


Nutrients and fertilizers have a great influence on the growth of the plant. Therefore, growers need to pay attention to each stage of development and choose the right fertilizers.

Hopefully, with the detailed information, you can take good care of your cannabis garden. Wishing you choose to buy and use the right fertilizers to have high-yield and high-quality harvests.

If you have any questions or concerns related to the topic “nutrients and fertilizer for cannabis plants”, do not forget to leave them in the comment so that we can assist you as soon as possible.


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