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Cannabis plants require nutrients to grow healthy. Feeding them with nutrient rich fertiliser can help your plants develop fast and produce better quality yields. Cannabis plants are sensitive to nutrients so you will need to be careful when feeding them. Too much can cause nutrient burn but too little can cause deficiencies. In this article you will learn more about cannabis nutrients and how to use them. 

  

Understanding Cannabis Macro And Micronutrients

Cannabis plants require three nutrients in large quantities. These important macronutrients are nitrogen (N), phosphorous (P), and potassium (K) and they form the foundation for healthy growth and development.

Macronutrients, however are not the only nutrients your cannabis plant will need. It also needs secondary nutrients like calcium, magnesium, and sulphur.

Calcium - this is important for the development of the cell wall, it can also help reduce soil salinity and improve water penetration when used as a soil amendment.

Magnesium - plays an important role in photosynthesis and carbohydrate metabolism. It also helps with stabilisation of the plant cell walls.

Sulphur - necessary for formation of chlorophyll and the protection of proteins, amino acids, enzymes and vitamins and also protects plants against disease.

Last but not least your plant will also use several other nutrients in smaller quantities than the macro and secondary nutrients. These include boron, copper, iron, chlorine, manganese, molybdenum and zinc. Although these are not the main nutrients your plant uses for food, they still have important roles in various aspects of plant health.

 

The NPK Ratio

When you buy a fertiliser it should have three numbers on the front of the package. These numbers represent the ratio of the three major building blocks for plant growth; nitrogen (N), phosphorous (P), and potassium (K). Together they make up the NPK ratio. The numbers of the NPK ratio will vary between products but they are always placed in the same order. This ratio will indicate the amount of nitrogen (N), phosphorous (P), and potassium (K) present in the fertiliser. The amount of each of these nutrients your plant needs will change depending on the growth stage it is in.

 

   Nutrients for Cannabis Seedlings

 

 

      

Very young cannabis seedlings get their nutrients from their seed and absorb water via the leaves and their root system. You will only need to start feeding the plant nutrients when they are about 3-4 weeks old and have developed 3-4 true leaves. This is when you know it has entered into the vegetative stage.

   

   

    

 

 

 

 

 

 

 

     Nutrients for Vegetative Stage

 

 

  

    

During the vegetative stage you will want to feed your plants nutrients that are high in nitrogen. Nitrogen will help your plant produce luscious, green foliage and develop lots of bud sites in time for flowering. Your plant will still need phosphorous and potassium but in smaller amounts compared to nitrogen.

Towards the end of the vegetative stage, it is a good idea to start lowering your nitrogen levels and preparing your plant for the switch into the flowering stage. 

  

     

      Nutrients for Flowering stage

  

   

   

 A plant in the flowering stage will need less amounts of nitrogen and more amounts of phosphorous. Phosphorous helps to promote the growth of large, resinous flowers. You want your plant to focus its energy on developing flowers and not green foliage like in the vegetative stage. 

  

  

  

  

  

 

Organic or Synthetic Nutrients?

When looking at nutrients for your cannabis plant, you will see that some brands make organic nutrients and some make synthetic nutrients. Every grower will have their own preference in which type they prefer. 

 

Organic Nutrients

Organic nutrients are made from only living organic sources like plant or animal waste. Organic nutrients are released into the soil and absorbed by the plant at a much slower rate than synthetic nutrients. This can greatly reduce the chances of nutrients burn and other feeding issues.

Benefits

• Less impact on the environment
• Boosts soil quality and health
• More sustainable than chemical fertiliser
• Some growers say it gives a better taste
• Improves soil quality and health

Drawbacks

• Absorbed much slower which can make it more difficult to solve a deficiency quickly
• Can cause algae and other unwanted fungi in hydro systems

 

Synthetic Nutrients

Synthetic nutrients contain the minerals needed for plant growth in a form that is instantly available for plants to absorb. The nitrogen comes from an artificial nitrogen fixation process called Haber-Bosch process and the phosphate and potassium are extracted from minerals, with harmful impurities removed.

Commercial synthetic fertilisers are carefully manufactured to contain a specific ratio of these three main minerals, shown in the N-P-K ratio, which stands for the percentage of each mineral that is in the product. Along with nitrogen, phosphate and potassium in specific ratios, other beneficial minerals like calcium, magnesium, iron, zinc and others can often be found in synthetic fertiliser products as well.

Benefits

• Absorbed faster
• Nutrient ratios are dialled in which gives you more control
• Faster growth
• Good choice for hydro systems

Drawbacks

• Fast absorption also means increased risk of nutrient burn if overfed
• Salt builds up in the soil over time
• Not made from renewable sources 

  

Differences Between Fertilisers

Not all fertilisers are made the same. The NPK ratio will differ, as well as the ingredients.

Here are some guidelines when choosing your nutrients: 

Nutrient ratio: Check the ratio to make sure it is right for the stage your plant is in. A grow nutrient should be used for the vegetative stage and a bloom/flowering nutrient should be used during the flowering stage. 

Ingredients: Some fertilisers are made only from organic ingredients and some are salt - based synthetic ingredients.

Soil or hydro: Make sure you are buying the right types of nutrients meant for your grow medium. Nutrients are made for specific grow mediums. Some are meant to be used in soil, some are meant to be used in hydroponic mediums such as coco coir and some can be used in both types. It is important to make sure you buy the best fertiliser for your grow system. 

Supplements: Many fertiliser brands also make supplements. These products will typically have a low NPK ratio and will instead, focus on boosting certain aspects of growth.

 

It's all about that base!

Hydroponic nutrients are commonly available in the form of concentrated liquid or powder. These base nutrients are often available in 1,2 and 3 parts, but what is the difference?

What Are Base Nutrients?

Base nutrients are the essential food your plant needs to absorb in order to thrive. Just like humans, your plant needs a balanced diet that contains all essential elements for growth. Your base nutrients is what will provide these essential elements. All kinds of additives can be added throughout the grow cycle, but your base nutrients are the building blocks for strong healthy plants. There are many types of nutrients available for different growing media, like soil, coco and hydroponics and are normally made in either 1 part, 2 part or 3 parts.

One-Part Nutrients

One-part nutrients are preferred by those looking for the simplest growing. They contain all the minerals your plant needs in one bottle. However, these one-part nutrients are often separated into two bottles, one being a 'Grow' and the other a 'Bloom'. Many beginner growers start with one-part nutrients as it is low-maintenance and mistakes are less likely to happen. 

Two-Part Nutrients

Many growers using the one-part nutrient go onto two-part nutrients to experiment.  You should note that two-part nutrients sometimes come in four parts. Two bottles for the grow stage (Grow A and B) and another two for the bloom stage (Bloom A and B). Manufacturers do this to separate volatile elements and produce nutrients at higher concentrations. This means the grower needs less product to make nutrient solutions. 

The other “true” two-part nutrient consists of just two bottles for your plant’s entire lifecycle. The key here lies in the ratio used by the grower. Depending on which part of the grow cycle your plant is in, a different ratio is required. For the grow/vegetative phase, a different ratio is required – usually according to the manufacturer’s instruction of the ‘A’ and ‘B’ stage than for the bloom phase.

Three-Part Nutrient

With three-part nutrient products, growers are given the most control, even though it also poses some risk of errors. However, if you are confident of your label-reading and measuring abilities, using a three-part nutrient should not be challenging. The three-part nutrient comes in three bottles; Grow, Micro, and Bloom. The whole idea is that growers use different ratios for the different part of the plant’s lifecycle and this way, they can care for the plants according to their specific needs. So, if you notice a drop in your Nitrogen levels even after the recommended feeding, a bit more Grow formula can be added to help correct it.

 

How to Apply Nutrients

Most nutrient brands provide their customers with a feeding chart. It is advised to follow these charts as they will provide you with important information such as the nutrient to water ratio as well as how often to feed. Nutrients are typically applied once a week.

Some charts may even provide a PPM range for the solutions. If so it is a good idea to invest in a PPM meter and measure your nutrients before feeding.

 

Some Final Notes On Cannabis Nutrients and How To Use Them 

Plant nutrition is very important to your plants health. Providing your plant with the right nutrition in each stage of growth will help it to grow healthy and strong and reward you with big flowers.

Always remember to flush. Nutrients are super important, but you don’t want any of them leftover in your harvested bud. That’s why it’s important to flush your plants with pH-neutral water for at least one week before harvesting. Flushing forces your plants to consume any leftover nutrients they’ve stored, resulting in a clean, smooth smoke.

Whether you choose to go organic or synthetic is completely up to you as the grower. The best thing to do is try it out and see which one works better for you and your grow.