Optimizing Cannabis Growth: A Guide to Macro and Micronutrients and Specific Nutrients for Every Stage of Growth

Cannabis is a versatile plant that can reward you with juicy buds if you take care of it. However, just like humans, it requires a range of nutrients throughout its life cycle to grow strong and healthy. 

From its tiny seedling stage to a bountiful harvest, every phase of growth requires specific nutrients with a unique role in promoting growth and development. Therefore, understanding the nutrients needed at each stage of growth is essential for achieving optimal yields and producing high-quality cannabis flowers.

But if this all sounds complicated, don't worry. We've got you covered! In this article, we'll spill the beans on the nutrients cannabis needs at every stage of its life cycle. Plus, we'll show you how each nutrient promotes growth and development and give you the inside scoop on ensuring your cannabis plants get the right dose at the right time. 

Whether you're a seasoned green thumb or a newbie, this guide will have you growing healthy, vibrant cannabis plants that'll make your buds the envy of all your friends. So let's get started on the path to optimizing your cannabis growth!

The Importance of Nutrients for Growing Cannabis

Nutrients are essential for the growth and development of living organisms, including cannabis plants. Typically, they are classified into two broad categories: macronutrients and micronutrients.

Macronutrients are required in relatively large quantities and include elements such as nitrogen (N), phosphorus (P), and potassium (K), which are all essential for plant growth and development. Plants usually obtain these macronutrients from the soil or other growing media.

Plants also need carbon, hydrogen, and oxygen, which they derive from the air. Many people focus on just the macronutrients but forget about the importance of these elements. While carbon, oxygen, and hydrogen are not typically considered "nutrients" like the other macronutrients, they are still essential components of plant growth and development. 

1. Carbon

While not technically a macronutrient, carbon is a necessary element for cannabis growth. The plant takes it up through the air in the form of carbon dioxide, which is used to build organic compounds like carbohydrates, proteins, and fats. Carbon is also necessary for energy production during respiration. Without adequate carbon, cannabis plants cannot grow or produce flowers.

Think of carbon as the backbone of the plant's structural components, as these compounds give plants the energy and structure they need to grow big and strong.

Cannabis plants also obtain carbon from organic matter in the soil. When plants or other organisms die, their organic matter breaks down and releases carbon into the soil, helping other plants that then absorb them.

This is why many growers use CO2 in their grow rooms to grow healthy cannabis plants. But does this mean that the more CO2 you provide, the better the plants grow? No. Like everything else in life, anything in excess can be detrimental. Therefore, you must remember that although carbon is essential for plant growth and survival, too much carbon dioxide in the air can harm plants and humans. High levels of CO2 can lead to decreased plant growth and health, as well as respiratory problems in humans.

2. Hydrogen

If you’ve grown even a single cannabis plant, or any plant, for that matter, you already know the importance of water.  Similarly, plants need water to survive. Cannabis plants use water to create hydrogen. The hydrogen is then combined with carbon during the process of photosynthesis, where the plants release oxygen into the air.  

3. Oxygen

Oxygen is equally important for cannabis plants as it generates energy during respiration. This is when the plants break down organic molecules such as sugars to release energy, fuelling the plant's growth and development. Plants absorb carbon dioxide (CO2) from the air, which is then combined with water to produce glucose and oxygen.

Basically, these three elements work together to help cannabis plants grow, develop and produce flowers. Carbon provides the foundation for plant structure, hydrogen is crucial for water and nutrient transport, and oxygen is necessary for respiration and photosynthesis. Without these three elements, cannabis plants cannot grow and produce high-quality buds. While you don’t have to provide these elements in the form of nutrients, you should provide the right environment for your cannabis plants so they get everything they need to thrive.

In addition to these essential elements, plants also require a range of other substances, such as vitamins and hormones, that are not typically classified as nutrients but are still important for healthy growth and development. 

Role of Primary Macronutrients

Macronutrients are the essential elements that cannabis plants need in large amounts to grow healthy and strong. Nitrogen, phosphorus, and potassium are often referred to as the primary macronutrients, while calcium, magnesium, and sulfur are considered secondary macronutrients.

Picture this: your cannabis plants are like Olympians training for the big event, and they need a special diet to get to the top of their game! Just like athletes need protein, carbs, and fats, cannabis plants need their macronutrients to grow big and strong.

Nitrogen is like the plant's personal trainer, helping them build muscle and grow new leaves. Phosphorus is like the team nutritionist, ensuring the plants have enough energy to get through the day. And potassium is like the coach that makes sure the plants stay hydrated and balanced.

Let’s delve a bit more into the role of the primary macronutrients. 

1. Nitrogen 

Nitrogen is an essential macronutrient that is required for the growth and development of healthy cannabis plants. It is a critical component in producing chlorophyll, responsible for the plant's green color and ability to photosynthesize. Nitrogen is also necessary to generate amino acids, which are the building blocks of proteins. Without adequate nitrogen, cannabis plants may exhibit stunted growth, yellowing of leaves, and a reduced ability to produce flowers and buds.

2. Phosphorus

Phosphorus is another essential macronutrient critical for healthy cannabis growth. It plays a crucial role in developing roots and flowers and is essential for transferring energy from one part of the plant to another and photosynthesis. Phosphorus also helps the plant to withstand stress, making it an important nutrient during the flowering stage. Conversely, a phosphorus deficiency can lead to stunted growth, poor yield, and lower-quality flowers.

3. Potassium

Potassium is another primary macronutrient vital for healthy cannabis growth and stress tolerance. It helps regulate water uptake and photosynthesis and improves the overall quality of the plant's flowers and fruits. Potassium deficiency can lead to poor yield, reduced flower size, and weakened stems.

Role of Secondary Macronutrients

Coming to our previous analogy of the plants training for the Olympics, don't forget about the other players on the team! 

Technically, calcium, magnesium, and sulfur are considered secondary macronutrients. While calcium and magnesium are like the plant's physician, keeping their cells strong and healthy, sulfur serves as the plant's secret weapon, helping them fight off pests and diseases like a superhero!

Without these macronutrients, your cannabis plants might feel like they're running empty, out of fuel, and unable to reach their full potential. So make sure to give them the balanced diet they need to bring home the gold!

1. Calcium

Calcium is a secondary macronutrient essential for healthy cannabis growth. It is crucial in building strong cell walls and promoting healthy root growth. Calcium deficiency can lead to slow or stunted growth and damage the plant in several ways. 

2. Magnesium

Magnesium is another secondary macronutrient vital for healthy cannabis growth. It helps with chlorophyll production, making it necessary for photosynthesis. Magnesium also helps to regulate plant metabolism and enzyme function. A deficiency in magnesium can lead to leaf chlorosis and reduced growth.

3. Sulfur

Sulfur is a secondary macronutrient that is required in smaller amounts than the other macronutrients. However, your cannabis plant cannot synthesize proteins and enzymes without it. Sulfur deficiency can lead to stunted growth, yellowing of leaves, and reduced yield.

Role of Micronutrients

Micronutrients, on the other hand, are required in much smaller quantities and include elements such as iron (Fe), zinc (Zn), and manganese (Mn). However, even though they are needed in smaller quantities, their role is equally important in the growth and development of healthy cannabis plants. 

These micronutrients are often obtained by plants from the soil, but they can also be obtained from the air or water. 

Here are the key micronutrients and their roles:

1. Iron 

Iron is a micronutrient needed by cannabis plants for chlorophyll production and photosynthesis. Chlorophyll is responsible for the green color of plants, and its production is critical for healthy plant growth. Iron also plays a role in enzyme activation, which is essential for plant metabolism.

2. Zinc 

Zinc produces growth hormones and regulates enzymes. Like many other macro and micronutrients, it plays a key role in photosynthesis. Zinc is also necessary for the production of chlorophyll and helps the plant to deal with stress response and resist diseases. 

3. Manganese 

Manganese is involved in the process of photosynthesis and also produces chlorophyll. It plays a critical role in the metabolism of carbohydrates and nitrogen, and it is necessary for the proper functioning of enzymes. Furthermore, manganese assists in reproduction — a factor that’s crucial to produce seeds. Imagine what would happen if the plant couldn’t produce any seeds! Manganese also helps with stress response and resistance, and it is important for seed germination and root growth.

4. Copper 

Copper helps with enzyme activation, protein synthesis, and respiration. Copper is also important for plant stress response and resistance and helps with the absorption of iron. Last but not least, it helps the plants to metabolize carbohydrates. 

5. Boron 

Boron is essential for plant growth and development. It assists in the production of cell walls, and also helps the plant to develop strong roots and shoots. Furthermore, boron assists in flower development and is important for proper seed production. 

6. Molybdenum 

Molybdenum is involved in nitrogen metabolism and is required for the production of amino acids and proteins. Molybdenum also activates enzymes and helps the plant to absorb iron efficiently. Specifically, it helps the plants convert nitrite to ammonia. 

As you can surmise by now, micronutrients are crucial in growing fantastic cannabis plants. They are the difference between a plant that just survives and another that thrives. They are essential for proper photosynthesis, enzyme activation, stress response, and resistance, among other critical functions. Providing your cannabis plants with adequate amounts of micronutrients can help ensure healthy plant growth and optimal yields.

Nutrients Required According to the Stage of Growth for Cannabis

Growing cannabis is an exciting journey that requires a lot of love, attention, and care. However, providing them with the right nutrients at every stage of their growth cycle is critical. Let's dive into the specific nutrients your cannabis plants need at each stage of their growth.

1. Germination

Period: 4 days - 15 days after germination

During germination, cannabis plants rely on the nutrition stored in their cotyledons to provide them with the necessary energy and nutrients for their initial growth. Cotyledons are the first set of leaves that emerge from a seed. They hold the fort and take charge of photosynthesis until the plant develops its true leaves.

The cotyledons contain carbohydrates, proteins, and fats, which are broken down to provide energy for the plant to grow. This way, the plant initially survives for at least 10-15 days. Then, as it grows, it begins to develop true leaves and starts to rely on the soil for nutrition.

Nutrition and other factors

During the initial stage, you don’t need to provide extra nutrition as the cotyledons are enough for the plant to grow. However, it won’t hurt to use a seedling mix containing adequate phosphorus and potassium to help the seedling grow better.

• Cannabis seeds also need oxygen to germinate, so it's important not to bury them too deep in the soil. A depth of around 1-2 cm is sufficient, and the soil should be loose enough to allow air to circulate. 
• Use a seedling mix containing equal amounts of nitrogen, phosphorus, and potassium to promote healthy leaves, roots, and stems. However, use low amounts of nutrients. Most growers don’t use anything at all, and their plants still do very well. 
• Provide direct light, but it shouldn’t be so bright that it burns the seedlings. CFLs work well for this stage. 
• Remember to maintain moisture in the soil during this stage of growth, or there’s a risk of the seedling drying off. Moisture also ensures that the cotyledons can break down their stored nutrients efficiently. If the soil is too dry, the cotyledons may not be able to provide the necessary nutrients to support the plant's growth, which can result in stunted growth or even death. 
• The soil should be damp but not waterlogged, as excess water can drown the delicate seedling.

2. Seedling

Period: 15 days - 30 days

After 10-15 days, your cannabis plant will have sprouted a few sets of leaves. Therefore, you can start feeding them with the right balance of macronutrients. As the plant needs to develop more leaves, it will require nitrogen, but the seedling will also need phosphorus and potassium for stronger stems and roots. Of course, it will also need calcium and magnesium. Thus, rather than trying to calculate the ratios, it’s best to follow the feed chart provided by a commercial nutrient manufacturer. 

Most growers opt for an NPK ratio of 2-1-2, but it’s also not uncommon to use 3-1-2 for quicker results. This means the fertilizer or nutrient solution used during the seedling stage should contain approximately 2% nitrogen, 1% phosphorus, and 2% potassium. The higher proportion of nitrogen helps to promote early vegetative growth, and potassium promotes healthy root development.

Some commercial nutrients may also offer 4-3-6, so it depends on what you’re using. That said, be cautious and avoid using full-strength nutrients at this stage, as it can cause more harm than good. You can increase the nutrients gradually instead of going all out at once. 

3. Vegetative stage 

Period: 1-2 months approximately

The vegetative stage is a critical period in the growth cycle of cannabis plants, during which they undergo rapid growth, increasing in size and branching out with the formation of new leaves. To support this phase of development, the plant requires a balanced supply of essential nutrients, primarily nitrogen (N), phosphorus (P), and potassium (K). 

As mentioned already, nitrogen plays a central role in developing new leaves, stems, and branches. But don’t forget the importance of phosphorus as the roots grow rapidly too. The plant is now getting ready for the next stage, so it needs good amounts of all primary macronutrients.  

At this point, go for specialized fertilizers that contain higher levels of nitrogen and phosphorus. These fertilizers are formulated specifically to meet the increased demands of the cannabis plant during this growth phase, promoting healthy and vigorous growth.

While nutrients with 4-2-3 or 4-3-6 NPK ratios, for example, will work well, you can also use other ratios as long as there’s a balance of all nutrients. You can increase the ratios or opt for stronger nutrients as the plant progresses into the vegetative stage and develops more leaves. 

You’ll also need to introduce silica to help the plant grow strong at the cellular levels. Not to mention calcium and magnesium, along with all micronutrients. Your fertilizer may have a different NPK ratio, but your plants will do well if it has slightly more nitrogen. 

Typically, the manufacturer will provide part A and B or “Grow” and “Bloom,” and you can use the “Grow” part during the vegetative stage. Don't forget to add micronutrients if you’re supposed to add them separately. 

4. Flowering stage

Period: 2-3.5 months, approximately

During the flowering stage, your cannabis plants will shift their focus from growing leaves and stems to produce flowers. To support this process, your plants will require a lower amount of nitrogen and a higher amount of phosphorus and potassium. Phosphorus helps your plants produce bigger and denser buds, while potassium helps your plants resist stress and produce more resin. You can find fertilizers specifically formulated for the flowering stage containing higher amounts of phosphorus and potassium.

Just like the vegetative stage, you can gradually increase the nutrient strength as the plant transitions from its early flowering to mid-flowering and late-flowering stages. At this point, you should use the “Bloom” part since they usually contain more P and K compared to N. 

For instance, some growers use 2-7-4 during the early flowering stage and become more aggressive during the mid-flowering stages by using 6-10-15 NPK ratios. You can also use bloom boosters that typically contain 10-30-20 NPK ratios. 

5. Ripening/Harvest stage

The final stage of your cannabis plant's growth cycle is the ripening/harvest stage. During this process, your plants will require a lower amount of all macronutrients. Cannabis plants will focus on ripening their buds and preparing for harvest. Therefore, you should stop providing any nutrients a few weeks before harvest to ensure the final product is clean and free of residual nutrients. You can also flush the plants with plain pH-balanced water or avoid it, depending on your preference. 

Note that these values are just an approximate and can differ from one company to another. 

How to Read a Feed Chart

Everything is moot if you don’t know how to read a feed chart. While it’s not complicated, reading a feed chart accurately is essential to help your plants grow well. If you want to maximize the yield and potency of your plants, you might want to pay close attention to feed charts!

In short, a feed chart is like a nutritional guide that tells you exactly what your plants need to grow healthy and strong throughout their different stages of growth. The chart typically lists the different stages of growth, including seedling, vegetative, and flowering stages, and provides a breakdown of the nutrients required for each stage. 

Now, here's the catch: not all feed charts are created equal! Different fertilizer brands have different formulas and ratios of nutrients, and some might even include micronutrients in the mix or offer them separately. That's why it's crucial to understand the feed chart that comes with your chosen brand of fertilizer. 

But don’t worry. Once you get the hang of it, a feed chart can be your best friend in the growing process. It typically lays out a growing cycle that lasts for about 12-13 weeks, depending on the manufacturer. 

Generally, each week will be listed in rows along with necessary information about Micro, Grow, and Bloom parts as well as any supplements the plant may need. However, this may vary from one manufacturer to another, depending on how they formulate the nutrients. 

The most important information you’ll need to know is the amount of nutrients to feed your plants. It will also specify the ratio according to the growing phase. For example, you already know that the plants need more nitrogen during the vegetative phase, whereas you’re supposed to feed more phosphorus during the pre-flowering stage. It’s pretty easy to understand once you learn what your plants want. 

We recommend that you stick to the feed chart of your favorite brand and get used to it. But, remember that while one plant may respond positively to the nutrients you’re feeding, another plant may not perform the same. Thus, you can tweak the nutrients a bit, depending on how your plants react to them. 

While it’s okay to feed less than the recommended dosage during the seedling and early vegetative phase, it’s not a good idea to feed more than the manufacturer’s recommendations as you may encounter a host of other problems including nutrient burn. Some growers assume that more nutrients equate to healthy plants, but remember that less is more for cannabis plants. In fact, they will survive in good soil even if you don’t add extra nutrients, but the plants may suffer even if the soil contains too many nutrients. 

In addition, try not to mix too many nutrients aside from the nutes you’re already feeding as it can complicate things. Some companies are very detailed and also recommend the pH and ppm values. But, even if they don’t, you’ll need to check the values after feeding the plants and make any necessary adjustments every single time. This is crucial because fluctuations in pH can cause major problems for your plant. 

In summary, here are the steps you should follow to ensure the plants get all the necessary macro and micronutrients as listed on the feed chart:

• Understand the phase of growth: Make sure you know whether the plant is in the vegetative or flowering phase consulting the feed chart.
• Identify the nutrients: The feed chart will list the nutrients your plant needs to thrive, usually abbreviated with letters like N, P, and K. Each nutrient plays a vital role in your plant's development, so you must know what they are and what they do.
• Check the recommended dosage: The feed chart will recommend a specific dosage for each nutrient at each stage of growth. Following the recommended dosage is crucial to avoid overfeeding or underfeeding your plants, which can lead to stunted growth or nutrient burn. 
• Adjust for your growing environment: Remember that the recommended dosage on the feed chart is a general guideline. You may need to adjust the dosage based on factors like the type of soil, the size of the container, and the intensity of the light source. With a little experimentation, you can find the perfect balance for your plants.

How to Prepare and Feed Nutrients to Cannabis Plants

If you’re a beginner, you may want to know how to feed nutrients to your cannabis plants. It’s pretty simple. So, here goes:

• Measure out the nutrients: Use a measuring cup or scale to accurately measure the nutrients according to the feed chart and follow the recommended dosage. 
• Mix the nutrients with water: Add the nutrients to a container of water, mixing thoroughly to ensure the nutrients are fully dissolved. The feed chart should provide you with a recommended ratio of nutrient solution to water.
• Check the pH of the solution: The pH of the nutrient solution should be between 5.5 and 6.5 for optimal absorption by your plants. Use a pH meter or testing kit to check the pH level and adjust it accordingly.
• Feed your plants: Pour the nutrient solution directly onto the soil or growing medium around the base of your plants. Be sure to saturate the soil without overwatering, and avoid getting the solution on the leaves or flowers.
• Check pH: After feeding your plants, check the runoff that collects in the drainage tray. The pH and nutrient levels in the runoff should be similar to that of the nutrient solution. If the levels are off, adjust the pH and nutrient levels accordingly.
• Adjust as needed: As your plants grow and develop, their nutrient needs may change. Consult the feed chart and adjust the nutrient solution and dosage as needed.

And that’s it! You now have all the information needed to know about the nutrients of cannabis plants. Hopefully, you’ll have loads of buds and enjoy them!

Summary: Optimizing Cannabis Growth: A Guide to Macro and Micronutrients and Specific Nutrients for Every Stage of Growth

Cannabis plants need both micro and macronutrients to grow healthy and strong. As a grower, you should differentiate between the various stages of growth and provide nutrition as needed. In addition, provide supplements so the plants grow to their maximum potential. 

This guide gives you all the information you need to know about nutrients. Happy growing!