Nutrients that your marijuana plants need to grow

How many nutrients does your marijuana plants use?

Cannabis plant nutrition involves understanding how chemical elements play a role in your marijuana plants survival and overall health during the grow cycle. There are 16 chemical elements that make up the entire buffet of marijuana plant nutrition. These 16 chemical elements or separated into two major categories: 1) non mineral and 2) mineral. Each nutrient plays a specific role when you are trying to grow big and healthy cannabis plants. The mineral nutrients are hydrogen, oxygen, and carbon which are usually found in the air or in water molecules. Photosynthesis converts these non-mineral nutrients into sugars that your marijuana plants can use to grow.

What are the mineral nutrients that your cannabis plants will need?

The other big category of chemical elements that marijuana plants will use are the mineral nutrients. There are a total of 13 mineral nutrients that the cannabis plants will absorb from the soil through the root system.  Marijuana plants can also absorb nutrients through their foliage, or the leaves. The mineral nutrients can be grouped into two different categories: a) primary nutrients and b) secondary nutrients. Primary nutrients make up what is called the NPK ratio and is found on a lot of labels of  marijuana nutrient containers. These primary macronutrients are: nitrogen (N), phosphorus (P), potassium (K).  The secondary macronutrients are calcium, magnesium and sulfur. Your cannabis plants will need a good amount of macronutrients but will also use trace elements of micronutrients.


Photo Source:


Summary of Nutrients that your marijuana will need:

Primary Macronutrients (NPK): nitrogen (N), phosphorus (P), and potassium (K)

Secondary Macronutrients: calcium (Ca), magnesium (Mg), and sulfur (S)

Micronutrients – boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo), and zinc (Zn)

As mentioned before, the NPK ratio is the ratio of the three primary macronutrients found on a label for marijuana nutrients.  Here is a good rule of thumb for marijuana growing with respect to macronutrients: Nitrogen is for roots, Phosphorus is for building stems, and finally, Potassium (K) is used for flower formation. This means that in the beginning of vegetative phase, your cannabis plants will use a lot of nitrogen to establish initial leaves and a root system. Your marijuana plants will also use a lot of Potassium (K) during the veg phase to start growth and help with plant pathogens. In the flowering stage, your cannabis plants will want to use a lot of Phosphorus (P) and Potassium (K). Phosphorus will help increase the number of spots where your marijuana buds will form and Potassium is used heavily during bud formation.

Table shows how NPK is used by your cannabis plants in veg vs flower

npk usage for marijuana

We will look at three stages of cannabis plant development and discuss what nutrients are needed at each of these stages of growth. These three stages are seedling or clones , vegetative phase,  and the flowering phase. Your cannabis plants will need different things depending on where it is in its grow cycle.

If your cannabis plants are in the early stages such as seedlings or clones, you will not want to use any nutrients as you might risk burning your young ones. The only things that you should consider using at this stage are root beneficials such as healthy bacteria and fungus (mycorrhizae & trichoderma). These beneficial microorganisms will help break down the nutrients for the cannabis plant’s root system to easily absorb. This process is known as chelation.

After you take your cannabis clones and have transplanted into your grow pots, you are now starting the vegetative phase. Your cannabis plants will need high levels of nitrogen, medium levels of phosphorus, and medium levels of potassium. The cannabis plants will use all three of those macronutrients and trace elements of micronutrients to build tall, thick marijuana plants prior to going into flowering.

Once your cannabis plants enter the flowering phase, they will need a different kind of diet nutrient diet than what they were using while they were in the vegetative phase.  With regards to nitrogen, the opposite is true in this growth phase. Your cannabis plants will require very little of nitrogen, a medium level of phosphorus, and a high level of potassium. As mentioned before the phosphorus helps increase the number of spots where your marijuana buds will form and the potassium is used for the actual bud formation. During the last week or two of your flowering phase and right before you chop your plants, you should be flushing your cannabis plants so they are devoid of any nutrients at the time you are harvesting. Smoking cannabis with nutrients in it results in the weed tasting harsh and crappy.

What does each nutrient do for your marijuana plants?

In the next section, we will look at every relevant macronutrient and micronutrient that a cannabis plant would use and briefly describes what role that nutrient has for your marijuana plants. Knowing what each nutrient does will help identify any nutrient deficiencies that your marijuana plants may suffer. On the flip side, too much of any nutrient will cause your cannabis plants to undergo nutrient lockout and with hat they may appear to have a chemical burn. It is recommended that you use a full line of nutrients and maybe start with half of the recommended dosage at first. See how the nutrients are impacting your marijuana garden before you start adding more nutrients to help make sure you don’t chemically burn your marijuana plants.

What are primary macronutrients that your cannabis plants use?

Nitrogen (N)

Nitrogen is an integral part of all living cells and is necessary for the transfer of energy. Nitrogen is used to make chlorophyll which is responsible for photosynthesis. It is integral in the growth of your young cannabis plants

Phosphorus (P)

Phosphorus is also an essential part of photosynthesis and is used for the formation of oils and sugars in your cannabis plants. Phosphorus will help transforms solar energy into energy that your marijuana plants can use and helps with rapid growth. it also helps start blooming and increases the spots where your buds will form

Potassium (K)

Potassium is also used for photosynthesis in the building of proteins that your cannabis plant need. it is essential for cannabis Bud formation and will impact the quality of your butt.

Image result for nutrients marijuana

Photo Source:


What are the secondary macronutrients that your marijuana plants use?

Calcium (Ca)

Calcium is used for the cell wall structure of your cannabis plants. and is used for the transport of other nutrients.

Magnesium (Mg)

Magnesium is also needed to make chlorophyll for your cannabis plants to use for photosynthesis. Magnesium regulates plant enzymes responsible for the growth of your marijuana plants.

Sulfur (S)

Sulfur helps with cannabis plant growth and gives your plants resistance too cold. sulfur is used by your plants for the production of proteins and also helps with the development of enzymes and vitamins needed by your plants. it will improve the root growth of your cannabis plants.

What are the Micronutrients that your cannabis plants will use?

Boron (B)

Your cannabis plants will use boron to regulate other nutrients. It is essential to fruit development and also aids in the production of sugar that is needed by your cannabis plants. Boron is used in the formation of the cell walls in your marijuana plants.

Copper (Cu)

Copper is very important for photosynthesis and the reproductive growth of your cannabis plants. It is also helpful in the metabolism of your cannabis plants metabolism of sugars and carbohydrates.

Chloride (Cl)

Chloride helps with the metabolism of your cannabis plants. It is necessary for osmosis and plays a role in the photosynthesis of your cannabis plants

Iron (Fe)

Iron is used by enzymes in your cannabis plants and is also necessary for photosynthesis. It helps in the electron transport of your cannabis plants.

Maganese (Mn)

Magnesium is needed with the enzymes of your cannabis plants to break down carbohydrates end helps metabolize nitrogen.

Molybdenum (Mo)

Molybdenum is needed by your cannabis plants when they metabolize nitrogen. It is important in building the amino acids needed for your marijuana plants.

Silicon (Si)

Silica has been showing to strengthen plant cell walls and improve. It also helps a marijuana plant’s resistance to the elements and helps with overall strength and health of your plants.

Zinc (Zn)

Zinc is required by many enzymes needed for healthy growth in your cannabis plants. Zinc is essential for breaking down of carbohydrates and regulates your plant’s consumption of sugars.

Your Comments


Suscribe for free E-book

Want to learn How to Grow Cannabis Indoors?

To download our free E-book "How to Grow Cannabis Indoors" please click here.