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Cannabis nutrients

Understand how to use cannabis nutrients and when to feed your plants

Cannabis nutrients can confuse a rookie grower!

Stop us if you’ve encountered this situation before. 

You’re preparing your first ever cultivation setup, rummaging the Internet to learn what you need for the task. You run into complex talk about minerals, elements, micro and macronutrients, and marijuana fertilizers. You’re unsure how to proceed.

Don’t look any further. Today, we’re running through everything you need to know about nutrients for weed to have your canna garden flourishing.

What are cannabis nutrients?

Marijuana nutrients are an essential part of your cultivation journey, but they don’t have to turn into the bane of your existence. Let’s explain the ins and outs of feeding your weed.

Weed plants require various elements from the environment to survive and thrive. Nutrients for cannabis are simply the concentrated version of what they’d draw from their surroundings. 

You feed your garden to boost harvest quantity and quality and enjoy healthy, happy crops. These nutes aren’t anything to fret over. You’re giving your herbs a nudge in the right direction, supporting their natural needs. 

Now that you know what cannabis nutrients are, let’s discuss the various elements under that umbrella.

What nutrients does a cannabis plant need?

Weed nutrients include essential (macronutrient), micronutrient, and trace chemicals. Any quality solution for your garden contains a combination of these different elements. 

Macronutrients (NPK)

NPK is the big three among marijuana plant nutrients. The abbreviation stands for nitrogen, phosphorus, and potassium, and each plays a role in herb health.

  • Nitrogen (N) keeps the leaves green and the plants satiated. It’s vital for photosynthesis.
  • Phosphorus (P) aids both photosynthesis and energy transfer. As such, this cannabis nutrient helps seedlings mature, and it especially boosts flower production.
  • Potassium (K) helps plant growth and triggers enzymes necessary for many important processes, such as metabolism and sugar transport.


NPK isn’t the be-all-end-all of marijuana nutrients. Secondary elements, also known as micronutrients, act as support mechanisms for various processes in the seed-to-harvest progression. 

  • Calcium assists cell development, helping your seedling develop into a lush green beauty.
  • Magnesium is the central element of chlorophyll molecules. It supports leaf greenery and stimulates photosynthesis.
  • Iron supports chlorophyll production, boosting the feeding process.
  • Copper is another cannabis nutrient for photosynthesis. It also encourages various other processes that make plants prosper.
  • Sulfur exists in amino acids, aiding protein production and chlorophyll molecules for the overall integrity of your weed. 


Apart from macros and micros, trace cannabis nutrients can make or break your weed crop health. 

  • Carbon determines yield size and quality and supports cannabinoid and terpene production.
  • Hydrogen manages the pH levels of the soil or other growth medium, participating in nutrient consumption and plant health.
  • Oxygen delimits the rate of nutrient and water uptake in the root system.

Fertilizer types

Weed fertilizers are plant food products to optimize everything from seed to harvest. They help nourish the soil and cannabis plant, carrying it to its full potential of height, yield, cannabinoid production, and flavor.

When choosing the best marijuana fertilizer, you have two main product types to consider.

Artificial fertilizer

Artificial, commercial fertilizers for marijuana come in powder and liquid forms, available at most gardening shops.


  • Accessible and affordable.
  • Tidier and more straightforward than organic options.
  • Fast-acting and efficient.


  • Less powerful.
  • Leave a chemical flavor.

Organic fertilizer

Organic nutrients

Natural fertilizer for cannabis consists of worm castings, blood or fish meal, compost tea, bat guano, and similar ingredients. It’s a messier process to have this on the ready, but it creates a wealth of nutrients and a fully organic growing setup.


  • Higher-quality, organic cannabis.
  • Made from natural, eco-friendly sources.
  • No need for flushing.


  • A messier process.
  • Less precise than artificial fertilizers. 

The best fertilizer for marijuana in your garden is the one that gives you the most control over the growing conditions and suits your needs, dedication, and preferences. 

The importance of pH and water temperature

You can have the best nutrients for cannabis in the world—they don’t make much difference if your crops can’t use them for development.

Soil pH levels and water temperature make a world of difference in this context.

If pH levels go too high or too low, a nutrient lockout happens, leading to cannabis deficiencies and a whole lot of trouble. Keep a pH meter ready and maintain these levels for optimal absorption conditions:

  • 6.3–6.8 in soil
  • 5.5–6.1 in hydroponics

Also, as a rule of thumb, cannabis plants find it easiest to catch nutes from water in the 67–68°F range.

Cannabis nutrient-related problems

Cannabis nutrients are indispensable. Naturally, having too much or too little causes plant health issues. Here are the most common cultivation pitfalls you might encounter in this department.

Nutrient burn

Cannabis nutrient burn occurs when you use cannabis nutrients in too heavy concentrations—proving you can have too much of a good thing. 

The specifics differ from one element to the next. In most cases, nutrient burn in cannabis affects foliage first, leading to stains and discoloration. 

pH imbalance

As discussed earlier, roots can only absorb the nutrients in a limited pH range. Too acidic or too alkaline conditions lock out specific elements, preventing uptake.

pH imbalances are often the culprit for cannabis nutrient issues, not a lack or overabundance of a certain element. 

Nutrient lockout

Nutrient lockout in weed occurs when the roots can’t take in the nutrients, even if there’s more than enough of them to go around. It’s often the result of a pH imbalance or a high salinity (salt in the soil), both of which respond well to flushing.

Nutrient deficiency

Cannabis nutrient deficiency

Cannabis nutrient deficiencies are the opposite of a nutrient burn. This issue arises when your herbs get too little of an element vital to their well-being. 

The symptoms vary from one deficiency to another. Here’s where you can find the rundowns of the most prevalent ones:

Learn to recognize the warning signs early and respond to them proactively.

What nutrients are good for each cannabis stage?

Cannabis nutrients are essential throughout the different phases of weed development. Requirements change from stage to stage, though. 

Providing adequate nutrition throughout is vital to a yield of healthy flowers. Let’s explore the ideal cannabis feeding schedule per growth stage.


Weed seeds are a wonder of nature. The little shell holds within everything a seedling needs to start developing a root system and leaves.

You won’t need any cannabis nutrients during the seedling stage. Wait before they’re 3–4 weeks old and have some leaves to call their own before supplementing with plant foot.


The early days of vegging are the time to provide some nutrients for growing weed. 

Some farmers choose a 2:1:2 NPK fertilizer for a week to ease the crops into leaf development. Others skip this step and start with a 4:2:3 NPK solution right away.

Things get much more aggressive by mid-vegging, especially with nitrogen, which should stay abundant until flowering. 


The flowering stage gets your crops hungry for phosphorus and potassium. Nitrogen requirements reduce, and the plants dedicate energy to their budding flowers. 

Potassium needs to be higher than the rest. All the best nutrients for flowering are K powerhouses.

Cannabis nutrients: FAQs

Let’s wrap up by answering some of the common cannabis nutrient-related questions we hear in the community.

How often should I give my plants nutrients?

We hear growers often wonder, ‘how often should I give my plants nutrients?’ for fear that they’ll do it too rarely or too often. They forget that the answer rests on their pack of fertilizer. 

Different products have different scheduling requirements. You’re always best off following the instructions.

What nutrients are good for flowering cannabis? 

The best marijuana nutrient solutions for the flowering stage are those with lower nitrogen levels and higher potassium and phosphorus. These two chemicals do the heavy lifting during flowering, after all. 

Calcium is pretty useful for budding flowers, too, making them firm and chunky.

When to switch to flowering nutrients?

The emergence of pistils presents the right moment to reduce your nitrogen and boost your potassium and phosphorus.

The flowering stage signifies that your cannabis plant is finished with its vegetative growth for the season. It now needs the energy to produce flowers and coat them in resin.

Should I use nutrients every time I water? 

The cannabis feeding schedule depends on the manufacturer. 

Some fertilizers are less potent than others, requiring a dash of feed to every watering. Others do their job once every four weeks. Read and use the instructions for the best possible results.

How do you add nutrients to soil? 

Unlike with marijuana hydroponic nutrients, growing in soil puts a barrier between the roots and the elements they should absorb. The easiest way to make your soil more fertile is by incorporating a cannabis nutrient booster or fertilizer into your waterings

Check the instructions to learn the ideal feeding frequency. Once you have that down, double the importance of regular water with a mix that adds nutrients to the soil.

When should I start feeding my plants with nutrients?

Marijuana plant food becomes important as soon as your herb enters the vegetative stage

Don’t give nutes to seedlings. They’re already getting everything they need, and extras can only harm baby cannabis. When leaves start using the sun as their primary source of nutrition, a nitrogen boost becomes a great idea.

When should I stop giving my plant nutrients?

A week or two before the harvest is the moment to stop feeding your cannabis and flush the soil. Cut the extras and cleanse with pH-neutral h2O to eliminate as much chemical buildup as possible and maximize the natural bud flavor.

Key takeaways

You now understand what elements your cannabis plants require to grow and prosper, and why each of them matters. You’re much better equipped to find the best fertilizer for weed, uncover deficiencies, burns, and lockouts, and keep your marijuana garden thriving. 

Stay tuned to our blog for more useful guides such as this one. We strive to help rookie and veteran growers every step of the way.