The 5 Best Marijuana Fertilizers and Nutrients in 2020


Light, Air, Water, and Soil are the four major elements that go into gardening. No matter what plant you’re growing these are the four major factors you need to take care of and everything will just be ok if you do so. While growing marijuana too, these are the four big things that need to be taken care of. However, the difference between someone who has just begun to grow and someone who is a pro at it is that a pro knows how to make the most out of these four elements. In order to achieve the most out of the soil, you need to provide it with fertilizers and nutrients on a timely basis.

No soil is perfect and adding nutrients and fertilizers to the soil helps the growers attain a desired level of perfection which is suitable for the plants. Over the course of this article, we shall primarily be talking about the best marijuana fertilizers and nutrients that you can buy off the web and use on your plants to ensure that they are getting a strong growth. While we shall be reviewing the best options that you can buy, we will also be addressing the basics by talking about what fertilizers and nutrients are and why are they important when it comes to growing marijuana

Why Do Your Marijuana Plants Need Nutrients and Fertilizers?

If you simplify it to the most basic level, the soil is basically nutrition-rich dirt. The whole idea behind growing your plants in soil is that the soil can absorb nutrients which the plants can keep using as and when it needs. Besides, that soils in different parts of the world are rich in different nutrients and organic substances which is good for the growth and development of the plant. Plants require different types of nutrients during different phases of their growth. The kind of nutrient combinations a plant needs during its early stages is different from what it requires during its blooming and flowering phases. However, there are some nutrients that can be provided during both the phases of the plant’s growth cycle.

In addition to that, there are macronutrients which aren’t a part of the main NPK (Nitrogen, Phosphorus and Potassium) nutrients but still need to be provided for additional growth and benefits. Then when it comes to fertilizing the soil you need to provide different types of organic elements such as bat guano, molasses, kelp, etc. Its a combination of all of these things that are needed to keep your plants healthy and to give them that extra edge that helps the flowers bloom better and the vegetation grow better. 

Understanding Cannabis Nutrients Better:

There are basically two kinds of nutrients that you can provide to your plants. The first of these are the primary nutrients, often referred to as the NPK nutrients. In addition to that, you need to provide certain secondary nutrients to enrich the soil as well. Here’s a detailed look at both these types of nutrients that the soil needs to grow good cannabis.

1. Primary (NPK) Nutrients for Growing Marijuana

When you look at any bottle of plant nutrients (especially cannabis nutrients), you will find three numbers written on it separated by a dash, in the X-Y-Z format. These are basically the NPK proportions – the proportions of Nitrogen, Phosphorus and Potassium present in the solution inside the bottle. Basically, if the bottle you are buying reads 5-8-2, it means over 50% of the solution in the bottle consists of Phosphorus, the second most active component in the solution is Nitrogen and the least of them is Potassium. You also need to know that which of the NPK nutrients is beneficial for your plants during different stages of its growth cycle. 

Nitrogen (N) is essential for the plants during their early phase of growth. During the marijuana plant’s vegetative phase, the best marijuana fertilizer and nutrients that you can provide to them should have a high concentration of Nitrogen. This is because Nitrogen helps the plants convert sunlight into energy helping them to grow faster. It also helps increase the green cover of the plants by helping the cells to multiply faster. Up next is Phosphorus (P), which is useful during the later stage when buds emerge and flowers begin to bloom. Finally, we come to Potassium (K), which is needed during both vegetative as well as flowering stages in small doses. It helps the plants with processes such as osmosis as well as helps control the stomata openings allowing the plants to breathe properly. 

2. Secondary Nutrients for Growing Marijuana

While the NPK nutrients are very important for growing healthy marijuana, you also need to ensure that you are providing all the other needed elements and nutrients to the soil too. These are the secondary nutrients which the soil needs in smaller doses. Some of the most popular examples of these are Sulfur, Magnesium, Zinc, Copper, Calcium, Manganese, Boron, etc. These don’t really add to the growth but control some other factors such as the smell and the taste of the buds, the pigmentation of the plants, as well as help the roots grow and get nourished. While these are not needed in large numbers, and sometimes are already present in the soil in small quantities, you cannot ignore them completely because their deficiency will begin to show symptoms in plants.

The 5 Best Marijuana Fertilizers and Nutrients

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Now that you know what plant nutrition is and why nutrients are important, let us take a closer look at the 5 best marijuana fertilizers and nutrients that you can buy off Amazon right away and begin enriching your soil! There are just so many nutrients and fertilizers out there in the markets that growers (especially those who are just starting out with growing) tend to get confused about which products to trust and buy and which products they should be avoiding. To make things simpler and easier for all growers, here’s a detailed look at the reviews of some of these products:

1. Cutting Edge Solutions UJB:2602 Uncle John’s Blend

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Coming out in the markets with a proportion of 0-0-2, this is a solution which is rich in potassium and needs to be provided to the soil which lacks in it! Providing this potassium mixture to your plants will help them get a boost in their metabolic activities and will help them grow better. This is important because potassium is responsible for a number of major features such as the opening and the closing of the plants stomata which helps the plant breathe, as well as the process of osmosis. 

In addition to that Potassium also aides in production and transfer of ATPs (plant sugars) all over the plant’s body. This is usually used as a foliar spray and carries a very low molecular weight. This is a very clean spray that does not leave any residues after you’ve used it. What makes it quite useful is the fact that Potassium is actually needed during both phases of the plant’s growth cycle and you will need it all the time. Finally, this is one of the best marijuana fertilizers and nutrients, especially during the flowering stage as that is when the plant needs a little bit of that extra energy to stay alive as all the resources are going in the production and growth of the flowers and buds. 

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2. Fox Farm Liquid Nutrient Trio Soil Formula: Big Bloom, Grow Big, Tiger Bloom

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Fox Farm is one of the most reputed and popular names in the world of growers. Anyone who does even basic research about plant nutrients is likely to come across this brand. Here in this package, you get a combination of three nutrients – two dedicated for different phases of the plant’s growth cycle and one which you should provide during both these phases. The ‘Grow Big’ fertilizer is meant for the vegetative phase and helps the growers increase the green foliage of the plants. ‘Tiger Bloom’ is the second component which is to be used during the flowering stage of the marijuana plant and will help you grow bigger buds. Thirdly, ‘Big Bloom’ is to be used during both the phases as the function of this nutrient is to strengthen the roots and sustain the growth of the plant. 

This is a complete package which helps you ensure that your plant is getting sufficient resources for all their stages of growth. Another advantage of getting this package is that it also comes with a pipette and a conversion chart which will help you understand the metric conversions so you know exactly how much of the nutrients you should be using along with the water. All in all, this is one of the best marijuana fertilizers and nutrients that you can get, and that too from a very trusted and reputed brand. 

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3. Advanced Nutrients Big Bud Liquid Fertilizer

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Advanced Nutrients is another popular brand for those growers looking forward to buying the best marijuana fertilizers and nutrients. They have very unique looking canisters with designs that are typical of their brand, making them easily identifiable! The company has been around for quite some time is a trusted name when it comes to growing marijuana. This is their ‘Big Bud’ fertilizer which comes with the tagline promise of “puts the big in your buds”. It is low in Nitrogen, contains about 25% Phosphorus and 75% Potassium in the proportions of 0-1-3.

This is particularly useful during the flowering stage as it helps your flowers grow bigger and healthier. Using this fertilizer also makes sure that your plants are generating good quality essential oils, terpenoids and phenols among other things. This gives a good taste and smell to the buds as well. There is a significant boost to resin production in your plant as well. It is to be used 2ml per liter. While this is a 1 liter canister, you can get it in packs of 0.250 liters, 0.5 liters, 4 liters, 10 liters and 23 liters as well.

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4. Flower Fuel 1-34-32

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Rich in Phosphorus and Potassium, the Flower Fuel bloom booster set comes out with a proportion of 1-34-32, which means that it contains only trace amounts of Nitrogen, but is rich in the other two substances. In addition to the NPK nutrients, this also carries in it some amounts of Sulfur, Boron and Molybdenum which are also great for the overall nourishment of the soil. This is a 250 gram pack which can treat about 200 gallons of water! Since this is not a typical liquid nutrient, growers need to use it carefully and it is strongly recommended that only expert growers make use of this. 

Using flower fuel helps you get bigger and better flowers. Only about 1/4th teaspoon of this mixture is to be added to a gallon of water during the flowering phase of the plant and you will begin to see the result in just about a couple of weeks where you will notice that the number of flowers as well as the overall quality of the flowers is improving by providing them with this flower fuel. It is one of the best marijuana fertilizers that you can find in the markets and it also comes in larger packages, offering up to 20kg.

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5. Humboldts Secret Starter Kit Pack

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Our final product on this list is the total package that your plants are absolutely going to love! This is the Humboldts Secret Starter Kit Pack, which comes with six products in it. The first two are the Base A and Base B fertilizers (grow and bloom nutrients) which are to be provided during the respective phases. They carry the NPK nutrients in just the right volume for the plants to grow better, but also carry some other necessary elements such as Calcium and Magnesium. 

Then there’s the Golden Tree additive, which activates various enzymes and helps increase the overall quality of the flowers that grow on your plants. Another flowering additive called ‘Flower Stacker’ also comes in this package which is rich in phosphorus and potassium and is beneficial during the early flowering stage of the marijuana plant. It has been noted that using this helps boost the flowering by upto 30%. Another package offers you with Plant Enzymes which are highly concentrated and help kill off diseases and infections that might otherwise affect the plant. Lastly, CalMag and Iron is an additive that provides secondary nutrition in the form of Calcium, Magnesium and Iron. This package is best suited for hydroponic growers. 

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Buyer’s Guide: How to Buy the Best Marijuana Fertilizers and Nutrients?

There are thousands of plant nutrients out there in the markets and several specific offerings for marijuana growers as well. In such a tightly competitive market, it becomes hard for growers to pick the best nutrients for their plants. However, here are some basic things that every buyer must know which will help them get the best marijuana fertilizers and nutrients which will suit their needs! Here are the things you need to watch out for:

1. NPK Ratio

The NPK ratio is an important thing and needs to be considered before you buy your marijuana plant. Plants at different stages of their growth cycle need different nutrients and you need to make sure your NPK ratio is right before you provide it to your plants. The simplest way is to make sure that Nitrogen-intensive nutrients are going in during the early stages and Phosphorus intensive nutrients are going in during the second half of the plant’s growth cycle. Potassium is needed at all times.

2. Powder or Liquid

Some nutrients come in powder form while others come in liquid form. The powder form nutrients are generally cheaper, and can pack in more nutrition in a limited package – making them a good option for growers who are looking forward to a cheaper solution but are willing to put in a little effort in mixing them in water. However, this is something we won’t really recommend for novice growers because sometimes they don’t mix so well and if you don’t have enough growing experience you might end up adding too much or too little of it in the water resulting in your plants getting overnourished or undernourished, both of which are dangerous. 

3. Secondary Nutrition

While NPK elements are important you also need to make sure that you are providing secondary nourishment and are getting nutrients which also pack in calcium, zinc, manganese, sulphur and other similar secondary nutrients which are essential for the growth of the marijuana plant. The best marijuana fertilizers and nutrients are rich in secondary nutrients as well.

4. Soil Nutrients or Hydroponic Nutrients

The nutrients that are created for soil-based marijuana plants are different in composition from the nutrients that have been created for hydroponic growers. Depending on what kind of plants you are growing, you need to make sure that you are getting the right kind of nutrients for your plants. 

5. Quantity

Always check the bottles and the packaging for the quantity so that you know how much you are getting! Most growers prefer buying large quantities at one go so that they can power through their entire season with one bulk purchase. However different growers have different ways of doing this but quantity is indeed something that you need to consider!

6. Brand Credibility and Price

Last but not the least by any means, brand credibility as well as price are both very important when it comes to buying nutrients for growing your marijuana plant. Considering that there are thousands of options available in the markets you must make sure you are buying from a reputed and credible brand. Pricing is the final thing that matters – and it is not to be taken lightly. Always set a budget before you start shopping else you might end up overspending!

What is Flushing? How to Flush Nutrients in Marijuana Plants?

Knowing what kind of nutrients to provide to your plants during different stages of their growth cycles is one thing. However, there’s one more thing that you need to know before we head into the FAQs and the conclusion – that is when to stop providing nutrients to your plants. In flushing, you start providing plain water to the plants instead of providing them with nutrient-rich water because over the months of growth, the soil and the leaves have stored certain nutrients in the form of nutrient deposits and they need to be cleared out before the harvest else they will have a negative impact on the taste and the quality of the bud when it is consumed. 

Marijuana growers need to know that they need to stop providing nutrients a couple of weeks before they plan on harvesting. Normally, harvest begins 8 to 10 weeks after flowering (based on what strain of weed you are growing). Hence flushing should begin about 6 to 8 weeks after flowering. This needs to be done to ensure that consumers are getting a ‘clean’ product that is free of all nutrient deposits. 

Frequently Asked Questions About the Best Marijuana Fertilizers and Nutrients

We get several questions about marijuana nutrition. Here are the answers to some of these questions about using nutrients and fertilizers for growing your cannabis plants:

1. What happens if you don’t provide nutrients to your plants?

If you don’t provide the nutrients to your plants they will remain undernourished, leading to the buds growing smaller, lesser leaves and foliage, as well as the ‘effect’ of the weed that you smoke will not be as good. 

2. What is a nutrient burn?

A nutrient burn happens when you provide excessive amounts of nutrients to your plants, and that leads to portions of the leaves or flowers curling up, or getting darker due to these excess nutrients. These can be treated in the early stages by reducing the dosage of the nutrients but if this continues the damage is irreversible.

3. What happens if I don’t flush my plants after using nutrients?

If you don’t flush your plants certain nutrition deposits will continue to remain on the flowers and leaves and other parts of the marijuana plant. This will lead to the final bud that you smoke having an unusually strong taste or smell, basically giving you what is called ‘bad weed’. 

4. What is foliar feeding?

Feeding is basically the process of providing water and nutrients to plants. There are several different ways of feeding your plants and foliar feeding is just one of them. In this method you spray the leaves of your plants with a fine mist of the solution you have created by mixing the nutrients in water. This is particularly beneficial when done for secondary nutrients. 

5. What are the ideal pH numbers?

pH levels need to be checked when providing nutrients to the plants. The pH needs to be adjusted for your plants to take the maximum possible benefit out of the nutrients that you are providing them. For soil based growth of the marijuana plants, the pH level needs to be between 5.8 to 6.5. For hydroponic growth, the pH levels need to be between 5.5 to 6.2. You can use test strips and/or digital meters to check your plant’s pH levels. 


We hope that you have a much better idea about plant nutrition than you did when you started reading this article. We also hope that our list of the 5 best marijuana fertilizers and nutrients has helped you choose the perfect growth potion for your plants! Do go through our buyer’s guide and FAQs for more information on nutrients for growing cannabis. If there are still any questions that you want to be answered, you can drop us a mail or let us know in the comments section and we shall get back to you as soon as possible! Till then…

….Happy Growing! 🙂


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