Best Bloom Boosters for Weed (Key Bud Nutrients)

flowering bud

Growing cannabis can be a challenge, especially if you’re new to the process. There are a lot of steps to learn and facts to be aware of. If you don’t educate yourself enough before growing marijuana, your results could be worse than you expected. 

However, there are ways to make your cannabis grow bigger, better, and faster. That’s what you get when you use the best bloom boost fertilizer and supply your cannabis plants with the best nutrients. 

In this article, we’ll be covering fertilizers and nutrients for your cannabis, as well as giving you some recommendations for fertilizers…starting with our #1 pick the General Hydroponics MaxiBloom fertilizer.

The fertilizers in your grow room have to be nourishing enough for your plants without causing nutrient burn. The best marijuana fertilizers strike the right balance. 

By the time you’ve read this article, you’ll be much better informed about everything you need to know when it comes to marijuana nutrients, fertilizers, and bloom boosters.

Best Bloom Boosters For Marijuana

Product Details
1. General Hydroponics MaxiBloom for Gardening

  • Works in any growing medium
  • Potent formula
  • Great value per ounce
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2. General Hydroponics FloraNova Grow & Bloom

  • Highly concentrated
  • pH-stabilized 4-8-7 NPK ratio
  • Perfect for flowering stage
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3. Fox Farm FX14092 Grow Big Liquid Concentrate Fertilizer

  • Works for most plants & flowers
  • Earthworm castings & Norwegian kelp for bigger blooms
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4. Advanced Nutrients pH Perfect Pack Combo Set

  • Includes extra chelates for better results
  • Can mix with other fertilizers
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1. General Hydroponics MaxiBloom for Gardening, 2.2-Pound

The General Hydroponics MaxiBloom fertilizer is a great choice for encouraging your marijuana plants to bloom. It can be used alone, without being mixed with any other chemicals. The nutrients within are dry but soluble in water. 

This fertilizer is also perfect for use in any growing medium. That includes hydroponics, soil, and grow mediums that use soil. It is particularly helpful for encouraging the growth of cuttings and seedlings. Its benefits last throughout both the vegetative stage and the growth stage. 

One good option for this fertilizer is to mix it with warm water inside a jar, and then shake it for several minutes. This helps the nutrients to dissolve, and you can then transfer the mixture to a watering can and fill up the rest with water. Another added bonus is that you can use this fertilizer for ordinary garden flowers too. 


2. General Hydroponics FloraNova Grow & Bloom Quart 

The unique formula of the FloraNova fertilizer combines the advantages of dried nutrients with the speedy application of liquid nutrients. That makes it stand out from the competition because you can get results quickly and easily.

It’s worth noting that it’s got a 4:8:7 NPK ratio, so keep that in mind – you can reread this article for a quick reminder. 

The FloraNova fertilizer is suitable for use in any grow medium, plus it’s already been pH-stabilized, meaning you don’t have to worry about that factor. Because it’s highly concentrated, you won’t need to use it much each time you apply it, so it will last for longer. That makes it great value for money too. 

However, it’s important to remember that this fertilizer needs to be shaken very well before you use it so that it has the best effect on your plants. 


3. Fox Farm FX14092 Grow Big Liquid Concentrate Fertilizer 

If you’re concerned about your fertilizer being good for the environment, then you’ll want to know what it’s made of. The Fox Farm FX14092 fertilizer is completely organic, meaning that it features multiple nutrient types. These include macronutrients and micronutrients like we cover later in this article. 

Examples of the nutrients it contains are Norwegian kelp and earthworm castings. These improve the strength of the stems and leaves on your plants and enable it to branch out as it grows, which is great for encouraging big blooms. 

Not only that, but growers also report that it’s a great choice for other plants in their garden. These include herbs, tomatoes, roses, various vegetables, and flowers. That means you don’t have to confine your use of fertilizer to your cannabis plants, and you’ve got a decent explanation should anyone ask why you’re buying it.


4. ADV Nutrients pH Perfect Pack (Grow, Micro, Bloom) Combo Set 1L 

You’ll find the product packaging from ADV Nutrients’ pH Perfect Pack is highly detailed and provides you with plenty of information so that you can make an informed decision. 

In brief, it’s a good fertilizer that beats its competition by including extra chelates inside its micronutrients than rival fertilizers. Chelation stops micronutrients from having poor reactions inside the soil, so it can help the fertilizer have a stronger effect on your plants. 

The formula used in the pH Perfect Pack also keeps costs lower than they otherwise would be, which is a bonus if you’re on a budget. The results are generally reported as satisfactory, however, you’ll need to be careful when you’re mixing it.

Some people recommend you do extra research online regarding this. You may even choose to mix it with other fertilizers or nutrients, but that’s up to you. 


5. MADAME GROW Fertilizer or Liquid Fertilizer 100% Organic Root and Growth Stimulator

Another great option if you want an organic fertilizer to boost your marijuana plant blooms is the MADAME GROW fertilizer. It’s got no additives or chemicals, and it’s derived from natural seeds. This combination ensures that the growth of your plants is encouraged in a non-artificial way. 

Beyond that, it also takes effect within days, leaving your plants with tougher stems, sturdier roots, deeper colors, and extra leaves. That’s a big change compared to before you started using this fertilizer, so if you’re looking for one that makes a big impact, then this is your best choice. 

You’ll also find that this fertilizer provides every single nutrient your plants need. Examples include all of the amino acids that are essential for your plant to survive and thrive. That means you don’t need to add any other nutrients to the plants. This fertilizer also helps your plants to move nutrients around and mobilize minerals. 

Cannabis Nutrients and Fertilizers

When you’re growing cannabis, it’s important that you give them the best nutrients, but if you provide excessive amounts, you can induce chemical burns. That’s something you most definitely want to avoid. 

Every nutrient that your cannabis plants need is found in their natural environment. But if you add your own, as well as the best bloom boost fertilizer, you’ll find your plants do even better. But before you add any nutrients, it’s important to understand more about the important ones and how they work. 

Key Cannabis Nutrients 

There are three nutrients in particular which stand out for their importance in growing healthy cannabis plants. These are nitrogen, phosphorus, and potassium. Together they form what’s known as the NPK ratio, and this is an important statistic when you’re buying the best bloom boost fertilizer. 

But there are also additional nutrients that your cannabis plants need, and those are calcium, sulfur, and magnesium. Calcium helps the cell walls in your cannabis, increases the salinity of your soil, and aids water penetration. Magnesium improves photosynthesis and boosts the metabolism of your plants. Sulfur provides the foundations required for chlorophyll to form and helps produce vitamins, proteins, amino acids, and enzymes.

Here is some additional information about the three most important nutrients – potassium, phosphorus, and nitrogen. 


Potassium has a wide range of functions that ensure optimal plant health. It supports a process called osmoregulation, which relates to the amounts of salt and water in your plants. Potassium influences the operation of pores in the leaves, which are called stomata. These allow your plants to exchange crucial chemicals like carbon dioxide, oxygen, and water.


Phosphorus is used to boost your buds. When the phosphorus levels are optimized, your buds will grow much larger. It also helps the availability of nutrients, which allows your cannabis plants to absorb them. Nutrients like these help to structure the plant as it grows through the phases. Without phosphorus, you run the risk of your plants never flowering at all.


Nitrogen spurs on the development of your cannabis plants when they’re in the vegetative phase. It influences chlorophyll composition, and without it, your plant will lack the ability to use energy from sunlight. It’s also an amino acid, without which your plant will be at a significant disadvantage. Not only that, nitrogen is an essential ingredient for cells to multiply and grow. 


All of the above nutrients are known as macronutrients, meaning that large amounts of each are required compared to other nutrients. These additional nutrients are known as micronutrients, and cannabis plants also require these. The only difference is smaller quantities are needed for your plants to be healthy. They are:

  • Molybdenum
  • Copper
  • Boron 
  • Manganese 
  • Chlorine 
  • Iron 
  • Zinc 

Each one plays a vital role in your cannabis plants, and to get the best results, your plant should have decent amounts of each, as well as the macronutrients we covered. That’s where a good fertilizer comes in, and we’ll cover that next. 

The Best Bloom Boost Fertilizer 

Fertilizers help your plants because they increase the percentage of nutrients in the soil and make it easier for your plants to absorb them. There are four areas in particular that you need to consider when picking an excellent fertilizer.

Firstly, the nutrient ratio needs to be optimized. That means ensuring the manufacturer of the fertilizer you’re planning to buy has mixed it correctly and that the mixture is sufficient for the marijuana strains you’d like to grow. You can find this out by reading the packaging online or in-store. 

Secondly, the ingredients of the fertilizer you intend to use are very important too. Different brands use specific ingredients, and some are worse than others. Typically, the key distinction is whether the fertilizer is artificial or natural. Ideally, you should aim for natural fertilizers because these will mimic the conditions closest to what your cannabis plants would experience in nature. 

Thirdly, the grow medium that you use will affect the fertilizers you supply. Some fertilizers are only designed to be used with soil, whereas others are intended to be used exclusively with hydroponic set-ups. You need to choose the correct one to get decent results.

Finally, you can also consider supplements that fertilizer companies produce. These have lower NPK ratios and make up for it with different nutrients that boost the growth of your cannabis plants. But your primary focus should be the nutrients that you’re supplying to your plant. Supplements may not be necessary and should only be considered if the results you’re getting are poor despite using fertilizer appropriately. 

Nutrients at Vegetation 

When your cannabis plants are at the seedling stage, it’s crucial to ensure they’re treated properly. They’re very sensitive at this stage of the growing cycle, and need the best possible care. 

The seed itself initially provides nutrients until the roots are developed enough. After that, they’ll start taking in nutrients from the soil. It’s important to provide extra nutrients for the first month until your plants have entered the vegetative stage. 

You can do this according to the 2:1:2 NPK ratio for the first week, but some growers choose a 4:2:3 ratio instead. You can find out which one your preferred fertilizer has by reading the details on its packaging. After six weeks, it’s time to boost the nutrients to a much higher level so that your plants grow to be strong. The most common ratio at this point is 10:5:7. 

The added nitrogen will promote the growth of bud sites and improve the quality of the leaves. As your plant finishes the vegetative phase, you should reduce the nitrogen. The best ratio is 7:7:7. After this, it will be time to use the best bloom boost fertilizer to speed up the next stage. 

Nutrients at Flowering 

When your plants are flowering, less nitrogen is needed, but it needs to be substituted with additional potassium. If you’re able to do this, your flowers will grow larger and look nicer. The most common ratio at the start of the flowering phase is 5:7:10. As your flowering progresses, you can gradually step up the nutrient levels to a 6:10:15 ratio. Finally, when flowering is coming to a close, you can reduce it to a 4:7:10 ratio. 

Using Nutrients and Fertilizers

Now that we’ve shared more information about the ratios of NPK, it’s crucial that you learn how to interpret those and use them. We’ll also look more deeply at the use of nutrients and fertilizers in the cannabis growth process. 

When you read the instructions for any nutrient bottles or fertilizer packages you buy, it will tell you the NPK ratio. This is something you’ll know from reading the previous section. But when it tells you a ratio like 4:7:10, you need to know what that means. It means that there is 4% nitrogen, 7% phosphorus, and 10% potassium. You can keep this in mind when you’re ensuring the ratios are correct in different stages of the growing process.

Liquid Nutrients 

You can buy some nutrients in liquid form, and these are usable no matter what grow medium you have. You can also use them outdoors as well. If you want to ensure you’re not overly exhausted by supplying nutrients, liquid nutrients are the ideal solution. You can use mechanical aids like hoses and drip lines to help you deliver them to your plants. 

Liquid nutrients are also easier for your plants to absorb because they can simply take them up through the roots. But this is a double-edged sword because if your plants take up too many nutrients at too rapid a rate, it can damage your plants and reduce the success of your endeavors.

If you intend to use liquid nutrients, you’ll want to keep them separately from anywhere else, ideally in a tank filled with water. You can then pour them into the water and mix it all together. Once you’ve done this, you’ll need to know the appropriate amounts of water to supply for your plants. Once you have this information, you can calculate the proper ratio in liquid form. 

To help you do this, you can use a schedule tracking the amounts of water you’ve supplied, how many nutrients you use and what type they are, and the regularity with which you water your plants. It’s important not to use liquid nutrients every single time, or your plants will be overwhelmed. Instead, you should use them intermittently. For example, you might water your plants for one day without the nutrients and then add them the next day, but not the day after that. 

The nutrient amounts required by your plants will also vary depending on your soil and how healthy your plants are. As always, the key is not to provide excess nutrients. To ensure that you give the correct amounts, you should observe your plants carefully. You can even start with a small dose of the growth solution until you think your plants are responding adequately. Once they are, you can move up to higher levels of nutrients. 

Another key area to focus on is the pH levels. These need to be just right. Your plants will prefer a pH of 6-7 in soil, and 5.5-6.5 in hydroponics. If you don’t keep the pH levels within this range, your plants can suffer something known as a nutrient lockout. That means your plants won’t be able to absorb nutrients. To avoid this, you should keep the pH at the correct levels and test it regularly. 

Organic Fertilizers 

Another phenomenon that you’ll come across regularly in marijuana growth is the use of organic fertilizers. The name is quite self-explanatory, and it refers to fertilizers that aren’t artificially created. These fertilizers often contain natural sediments that occur throughout the world, like gypsum and rock dust. Inside these sediments is a range of minerals that your plants will use to thrive. 

If you’re concerned about nutrient burn or supplying excess amounts to each plant, then you might want to forget about liquid nutrients and focus on these instead. You can get them from most local stores or online, and the nutrients they contain aren’t as soluble as what you’ll find in liquid nutrients. They also feature elements that help organisms present in the soil, which is an advantage that liquid nutrients don’t have. 

You can opt for a range of organic fertilizer solutions, and they include:

  • Bone meal, which adds phosphorus
  • Wood ash, which adds potassium 
  • Epsom salts, which add sulfur and magnesium 
  • Dolomite lime which adds magnesium and calcium
  • Blood meal which adds nitrogen 

You can buy these commercially too, so you don’t have to worry about preparing or mixing these ingredients together. When you use organic fertilizers, there is a range of benefits that you’ll notice. We’ll go through them below. 

Organic Fertilizer Benefits 

Organic fertilizers are often some of the best bloom boost fertilizer choices because of what they can achieve for your plants when used correctly. They’ll also help the soil, so it’s a win-win for your marijuana growth if you can use these. 

They’ll ensure your plants aren’t overwhelmed by releasing nutrients over time, and they’ll increase the biodiversity of your soil. They’ll also increase the ability of your soil to retain water and ensure a decent airflow throughout your cannabis plant root systems. It’s also good for the environment, as a renewable source of nourishment, plus nutrient run-off has a  reduced risk of occurring. 

However, some disadvantages are worth mentioning so that you’re aware of the consequences of using organic fertilizers. 

Organic Fertilizer Drawbacks 

When you use organic fertilizers for your weed plants, you’ll need to factor in what can happen when there is a nutrient deficiency. When this is the case, your plants will take longer to absorb nutrients, including ones supplied in a powdered organic form. 

Organic fertilizer use also needs microorganisms in the soil to break down the nutrients they contain. If the temperatures are low, this process can slow down, increasing the time it takes for your plants to grow. In addition, organic fertilizers can attract pests that will harm your plants. 

Bloom Boosters and Their Use

closeup of growing cannabis plant in grow tent with grow lights in background

Bloom boosters are a key part of growing marijuana, and it’s essential that you know about them and how to use them. We’ve already covered fertilizers and nutrients, and there will be a slight overlap with this section, but the differences should become apparent once you begin reading. 

Bloom boosters are essentially the nutrients themselves but in a highly concentrated format. You can get them as liquids or powders, and they use the nutrients we’ve discussed to benefit your plants. In particular, the best bloom boost fertilizer will focus on improving four areas of your marijuana. These are:

  • Its total yield 
  • The density of its resin 
  • The cannabinoid content 
  • The terpene content 

These will all be improved through the use of bloom boosters, making them powerful additions to cannabis plants. However, when you use them, there are some downsides, and two in particular. These are nutrient burn and stunted growth. We briefly addressed nutrient burn already, so we won’t spend extra time on that. 

But stunted growth occurs when your plant has excess nutrients. It will reduce the total yield and make the health of your plants decline. In some instances, your plants can even die, although this is a rare outcome. The key is to keep in mind that the best bloom boost fertilizer will have very high concentrations, so you don’t need to use a large quantity. 

When using bloom boosters, you should apply them during the first month of the flowering phase. In particular, weeks 2-4. These will help your plants bloom faster and give you a greater yield at the end of the process. These specific periods are because your plants have to metabolize the boosters, which means you have to provide them strategically.

Because bloom boosters are very strong, it’s worth only giving half of the dose the packaging states, just to be safe. If you need to add more, you can always do so later on. But chances are, your plants will be fine with the amounts that you’ve given. If your plants don’t react negatively to that dose, you can provide the full dose next time.

It’s also important to keep in mind that bloom boosters are only supplemental. It’s no good adding them to the exclusion of any other nutrients. If you do that, your plants won’t grow much differently from how they would have grown without adding these nutrients. That’s why adding the rest of the nutrients we’ve mentioned in previous sections is essential. 

Using the Best Bloom Boost Fertilizer 

Now that you know all the theories about bloom boosters, it’s important to factor in the actual process you’ll need to apply when you use them. That’s what we’ll cover in this section. To begin with, you’ll want a list of equipment and ingredients, and we’ll start with that. You’ll need:

  • A pH solution and meter 
  • Filtered water 
  • A nutrient meter 
  • A mixing cup 
  • The best bloom booster fertilizer 
  • Plastic syringe 

Once all of these are gathered together and laid out, it’s time for you to follow the steps below. 

1. Timing 

Before you begin applying the bloom booster to your plants, you need to look at the calendar and see if you’re in the correct phase of the flowering period. You can also use the instructions of the fertilizer to ascertain the right time. It’s also important that your plants are healthy when you want to apply the bloom booster. 

2. Instructions 

Once you’ve determined you’ve got the right timing, it’s time to read the packaging. That way, you can figure out the number of nutrients you need to add. An example is adding 2mL of nutrients for every 1 liter of water. If you were cautious with this, you would halve the dose to 1mL and see how your plants react to it. 

3. Mix 

After figuring out the dosage, you can mix the water and the nutrients, thus creating the mixture of bloom booster you’ll be applying to your plants. This is where the plastic syringe comes in. You can measure out liquid with it. Alternatively, if you have a powdered bloom booster, you can use a scale to do the measurements. You can then get the water and add the bloom booster to it. 

4. Measure 

Once you’ve mixed together the solution, it’s time to measure it to prove it’s ready to use. This is where you’ll use your pH and nutrient meters. You can find plenty of information about how to use them if you’re not sure, but otherwise, just complete the measurements and then make sure the pH range is in the figures we’ve given, and the nutrient range is appropriate too. 

5. Feed 

Your final step should be to provide the nutrient mixture to your plants. You can do this manually or by using a drip line. All you need to do is insert the mixture and ensure it reaches all of your plants. You’ll need to monitor them for 24 hours, but as long as you do that and your plants react well, then you’ll have successfully applied your bloom booster. 

If there are any problems, you may need to flush your plant, but it’s important to remember that all marijuana strains differ. 

Read Also: Weed Measurements

Frequently Asked Questions

When should I add a Bloom booster?

Apply Bloom boosters when plants begin flowering to enhance bud development. Best during early bloom phase, pre-flowering, and bud set.

How often to use bloom booster for weed?

Use a bloom booster every 1-2 weeks during the flowering stage of cannabis. Monitor plant response and adjust as needed.

What nutrients are best for flowering weed?

For flowering cannabis, prioritize Phosphorus (P), Potassium (K), Calcium, Magnesium, Sulfur, and trace amounts of micronutrients like Zinc and Boron. Avoid excessive Nitrogen (N).


You’ve now read our complete guide about nutrients, the best bloom boost fertilizer, and the best fertilizers to use when growing your marijuana such as the highly recommended General Hydroponics MaxiBloom fertilizer.

This should leave you informed about what to do when nourishing your plants with chemicals and light. 

You’ll also have some steps to follow so that you can improve your chances of using marijuana nutrients and bloom boosters appropriately. That way, you won’t have to search around extensively to figure out how to implement the advice we’ve given, and you can refer back to this article if you need any reminders. 

If you think you need additional information beyond what’s contained in this article, then feel free to browse around this website and read our other articles so that you can find out more. If you still need more information after that, you can take the subheadings included in this article and use them as search terms. 

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