How to Grow Fat Cannabis Buds: 8 Tips to Increase The Bud Size

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Added 27 December 2022

Big, fat juicy cannabis buds — who doesn’t like ‘em?

There’s something amazing about those big beauties that transport us into another world. 

Almost every cannabis grower aims to grow fatter cannabis buds rather than wispy ones that last just a while. 

And, why not? Big buds are a sign of a successful harvest. Plus, they have a richer terpene and cannabinoid profile with higher shelf appeal, which even your buyers will appreciate.

But if you assumed that the bud’s size depends on nature, you are partially wrong. While genetics does play a major role, there are a few things you can control to help your plant grow bigger flowers.

All you have to do is tweak a few things around. By planning the growth and harvest of your cannabis plant, you can help your plant grow fatter buds to a great extent.

Follow these tips to encourage your cannabis plant to grow fatter buds.

1. Fine Tune Your Light Setup

Fine Tune Your Light Setup

Light is the most important factor in fattening your cannabis buds. Light allows your plant to produce energy and sugar via photosynthesis, which eventually helps the plant grow bigger and fatter buds. 

Naturally, you won’t have to worry about the light if you’re growing cannabis outdoors, as nature works its magic on the plants. But, indoors? That’s a different ballgame altogether. You need to be meticulous about the light source, especially its intensity and spectrum. 

Let’s take a look at the two aspects of grow lights below.

  • The Intensity of Grow Lights

Intensity is nothing but the brightness of the grow lights during the daylight hours. A specific range of intensity is optimal for growing fatter buds, especially during the flowering stage. In the past, growers used 1000W per meter square for the best results.

These days, wattage is no longer an applicable way to gauge light brightness, thanks to the advent of LED lights as they consume much less energy while producing intense light.

For example, a modern 200W LED can produce light that a 200W HID cannot match. However, we aren’t talking about the cheap ones you get in most online stores. It takes a lot of time and expense to research, so you’ll find some of these LEDs expensive, but it’s all worth it at the end of the day. Just make sure you buy reliable lights from trusted manufacturers. 

Next, how do you find out whether your light is effective? You need to measure your light in lux or PPFD. Lux is the intensity of light falling on the surface — any surfer. An ideal range of lux you should aim for in your garden is between 35,000 to 85,000 lux or, more specifically, around 60,000 lux. 

But you can go a step further, too, with PPFD. For this, you need to understand what PAR and PPF mean. PAR stands for photosynthetic active radiation, which is a measurement of photons that activate the photosynthetic process in plants.

You can measure this PAR in two ways — photosynthetic photon flux (PPF) or photosynthetic photon flux density (PPFD). PPF measures the PAR photons of light, whereas PPFD measures the PAR photons of light at a specific surface in a second. 

PPFD is superior to lux because it only measures the kind of light your cannabis plant can use. And you can measure PPFD using a PPFD meter or even your smartphone, depending on its camera or light sensor. 

To grow fatter buds, you need to maintain the PPFD on your cannabis plant in the following ranges:

  1. Vegetative stage: 308 to 617 μmol
  2. Flowering stage: 462 to 926 μmol
  • Light Spectrum

The second most important aspect of light for growing fatter buds is the light spectrum; put simply, the light spectrum is merely the color of light your lamps produce. Essentially, different spectrums of light affect the plant in various ways, some of which lead to bigger buds.

Green to blue light, ranging from 490 to 570 nm, help the plant grow better by improving water absorption. On the other hand, yellow light, ranging from 570 to 585 nm encourages the plant to grow tall and start developing buds. And red light, ranging from 520 to 720 nm, increases resin production and bud size.

And not all types of grow lights produce the same color of light. MH or HPS lights don’t produce full-spectrum light. MH produces a more blue-dominant light and HPS produces a red-dominant light.

If your aim is to fatten up your buds, you should try to stick to light that is more on the red spectrum. You can either use HPS lights or choose LED lights. Again, LED lights are the better option here because they can let you control the color of light at every stage of the growth cycle.

2. Keep the Air Flowing

Keep the Air Flowing

Along the same lines, the next most important aspect of growing fatter buds on cannabis is the airflow. This is because cannabis has evolved to be pollinated by the wind and is designed to direct energy to the budding sites where there is optimal light and airflow. 

You can use this trait to your advantage and grow bigger, fatter buds — all you have to do is maximize the ventilation in the foliage and grow room. By allowing more airflow, you are encouraging the plant to direct more of its energy to the budding sites, which will lead to bigger, fatter buds.

If you are growing your cannabis outdoors, maintaining adequate airflow is as straightforward as placing your plants away from any obstructions and in a location that gets a lot of natural wind. Further, you can also prune some fan leaves off to improve the airflow. 

On the other hand, if you are growing cannabis indoors, you need to replicate the outdoor airflow, which can be done in various ways. The best way to improve airflow in your grow room is to invest in an air exchange exhaust system. 

An air exchange exhaust system consists of fans, vents, and exhaust, which constantly recirculate the air within the grow room. When installing this, ensure you place the incoming vent near the floor and the exhaust vent near the ceiling — hot air rises, so doing so will keep your grow room cool.

Additionally, you need to pick fans that can circulate enough air at a time. For this, take a look at the CFM rating usually marked on the fan’s packaging. Simply use your grow room’s volume to know the requirements and choose a fan accordingly.

A cheaper alternative to an air exchange exhaust system is an oscillating fan. This creates an active airflow within the canopy, not necessarily in your grow room. If you are a beginner grower, you can use this method as it is easy and affordable. 

Place a couple of oscillating fans aimed at your cannabis plants and ensure the fan is not fast enough to dry out the plant. Aim for a subtle yet strong breeze on the canopy. 

3. Give Your Plant the Right Nutrients at the Right Time

Give Your Plant the Right Nutrients at the Right Time

No doubt nutrients are important, but you need to administer them at the right time in the right ratios. Otherwise, your plant may not utilize all the nutrients well enough and grow healthily. This is because cannabis plants require different nutrients at different stages of growth. 

Let’s take a look at the common types of nutrients you need to give your plant and when.

  • Macronutrients

Macronutrients consist of the big three — nitrogen, phosphorus, and potassium — also known as NPK. These minerals are used by the cannabis plant in the largest quantities. Here, phosphorus is crucial for photosynthesis and potassium is crucial for bud development and terpene production.

So, to fatten up your cannabis buds, you must use bloom-specific nutrition products that are rich in phosphorus and potassium. The former will help the plant produce more energy and the latter will improve bud development. The final result would be bigger, fatter buds on your cannabis plant.

For the best results, feed your plant NPK nutrients in a ratio of 1:2:3 during the flowering stage. For the vegetative stage, the same ratio can be 2:1:3.

  • Micronutrients

Apart from macronutrients, cannabis requires various other nutrients in smaller quantities, which are known as micronutrients. And despite being used in small quantities, these nutrients are still essential for the plant’s development. 

Some of the important micronutrients include boron, calcium, copper, magnesium, zinc, etc., which help the plant grow structurally, leading to better bud development. 

  • Supplements

Apart from just nutrients, you can also administer various supplements such as bloom boosters to your plant. While not a lot of research has gone into the effectiveness of such supplements, many growers claim that supplements help their plants develop fatter buds. 

Most of the bloom-specific supplements include humic acids, trace minerals, vitamins, amino acids, and carbohydrates, along with phosphorus. You can buy these products at your local gardening store, but if you want to save some cash, you can use other natural alternatives, too.

Here are some alternatives to store-bought supplements:

  • Molasses

One of the best alternatives to store-bought supplements is unsulphured blackstrap molasses, which contains complex sugars and nutrients that maintain soil health and boost plant development. 

You can either use molasses as a foliar spray or add it to the nutrient solution. If you want to use it as a spray, add half a teaspoon to a liter of water, shake it, and spray it once every two weeks on the plant’s canopy. Fun fact: this solution also acts as a pest repellent, so it’s a win-win situation.

On the other hand, if you want to add molasses to the nutrient solution, you need to mix 5 ml for every liter of water a couple of times a week during the vegetative stage and 10 ml for every liter of water during the flowering stage.

  • Bone Meal

A bone meal is another terrific supplement that can help your plant grow bigger, fatter buds. This is a substrate amendment that contains ground-up animal bones.

What makes a bone meal so effective is that it is rich in phosphorus and calcium. Both are crucial for growing fat buds. As mentioned earlier, phosphorus encourages bud development and trichome production, and calcium boosts the formation of cells

Plus, bone meal isn’t the most vegan option out there. If you want to avoid this supplement, you can instead use kelp, which is made of seaweed and is just as effective

Both bone meal and kelp are easily available in most garden stores at affordable rates. And we recommend adding bone meal just when the first buds start appearing. But still, follow the manufacturer’s recommendation since the meals vary from manufacturer to manufacturer. 

4. Keep the Temperatures and Humidity in Check

Keep the Temperatures and Humidity in Check

Next, you need to keep the temperatures and humidity in check as the environment also has an immense effect on the bud development process. Cannabis plants prefer temperatures between 65°F to 80°F (18°C to 27°C) and relative humidity that starts at 70% but reaches 40% by the time of harvest. 

If the temperature and humidity are not in the recommended ranges, the buds will grow to be thin and airy, and in severe cases, they can even start popcorning. To control the relative humidity, you can use a humidifier or a dehumidifier, and an AC or fan can help you fine-tune the temperature of the grow room. 

5. Maintain the pH Levels

Maintain the pH Levels

Another essential thing you need to maintain for your cannabis plant is the pH level. pH is crucial for a plant’s health and development because it dictates the absorption of nutrients by the roots.

Cannabis plants prefer a slightly acidic pH, but if it strays out of the ideal range, the roots fail to absorb various essential nutrients, which can lead to nutrient deficiencies, nutrient lockout, stunted growth, and small buds.

So, when aiming for fatter buds on cannabis, you should never overlook the pH of the soil. If you are using soil as a medium, the pH should be between 6.0 to 7.0, and if you are using a soilless medium, maintain the pH between 5.5 to 6.5 for optimal nutrient absorption. 

6. Train the Plant 

Train the plant

Cannabis naturally grows in a Christmas tree-like shape, with one dominant cola and various side branches. In this shape, the main cola usually grows the biggest, fattest buds since it is best exposed to light and air. And the other side branches tend to grow smaller buds.

Training is a process where you don’t let your cannabis grow in a Christmas-tree-like shape, so side branches get just as much light and air exposure as the main cola. Alternatively, you can also train your plant to grow like a Christmas tree while still improving aeration and light exposure to the side branches.

Training not only increases light and air penetration within the canopy, but it also activates the plant’s defense, which improves bud development and trichome production in the plant — one of the ways it tries to defend itself against stressors. 

When you train your plant correctly, it can grow big, fat buds across all bud sites instead of just the main cola. And various training methods can be divided into two types: low-stress and high-stress. Let’s take a look at them below.

Low-Stress Training (LST)

LST or Low-Stress Training is not stressful for the plant. It involves bending and tying branches and pruning to maintain an even canopy where all bud sites can get an equal amount of light and air. 

If you are a novice grower or have never trained cannabis plants before, we recommend starting with LST as it is safe and gives you a lot of room for error before your plant gets affected beyond recovery.

The most common LST methods for fatter cannabis buds include the following:

  • Bending/Tying

Bending & tying is the most basic form of plant training, where you have to bend the branches and tie them down to create uniformity. In addition, it increases aeration and light penetration that results in fatter buds. 

  • Screen of Green (ScrOG)

ScrOG involves using a net or screen. In this method, you have to place a screen above the canopy and direct the branches through individual holes.

It’s somewhat of a long process but ends up creating an even canopy where all bud sites have equal exposure to light and air. The result is usually fatter buds with rich trichome profiles. 

High-Stress Training

There are other training methods that inflict more stress on the plant, known as high-stress training. And such methods are only recommended for experienced growers as they leave little room for errors.

Plants also require a longer recovery period when undergoing HST, so this type of training is only recommended if you’ve got some experience with it. 

Here are some of the common HST for growing bigger, fatter buds:

  • Pruning

Naturally, the lower branches of the cannabis plant do not produce big buds — those are reserved for the main cola. But these lower bud sites still consume a lot of the plant’s energy.

Instead, you can cut them off, allowing the plant to redirect all the energy to the higher bud sites that are already more likely to grow big buds. With more energy, they will grow even bigger buds. 

  • Lollipopping

Think of lollipopping as the more extreme version of pruning. Here, you basically prune away all the lower branches, which makes your cannabis plant look more like a lollipop and less like a Christmas tree. 

  • Topping

The opposite of pruning is topping, where you have to cut off the main cola to break the plant’s apical dominance. This makes the plant grow two colas. Keep doing this and your plant will have multiple main colas that grow bigger buds. 

7. Consider Adding More Carbon Dioxide

Consider Adding More Carbon Dioxide

Carbon dioxide is for your cannabis plant what oxygen is for us — the plant converts this gas into energy during the photosynthesis process. So, the higher the carbon dioxide in your grow room, the more energy your plant will be able to produce, leading to bigger flowers eventually. 

Generally, the CO2 concentration in your grow room is around 400 ppm, but by taking the concentration up to 1,200 ppm, you can increase your bud size by up to 25%! It is effective, but it may also be too expensive for many growers. 

Here are some ways you can add more carbon dioxide to your grow room:

  • CO2 Generator

The most effective way to introduce more carbon dioxide in a cannabis grow room is to use a CO2 generator, which resembles a heater and uses propane or natural gas to produce CO2. 

Do remember that if you are using a CO2 generator in your grow room, you need to slightly tweak the environment to compensate for excess CO2 — increase the temperature by 5 degrees and RH by 7%. 

  • Compressed Liquid CO2

Alternatively, you can also use compressed CO2, which you can buy from your local hydroponics or home brewing stores. With this method, you can add CO2 in a controlled manner by using emitter devices that allow you to control the flow rate of the gas. 

For most growers, compressed CO2 is better than CO2 generators because it does not produce excess heat, RH, or sulfur — the former two being bad for your plant and the latter being bad for your health.

  • Dry Ice or Compost

Easy but rudimentary ways to introduce more CO2 in your grow room involve placing dry ice or compost in the grow room. Both these methods are easy and affordable, but you cannot really control the rate of flow of the gas — you have to let nature drive this one. 

8. Be Patient and Harvest at the Right Time 

Be Patient and Harvest at the Right Time 

Lastly, you need to be patient. Flowers grow until the end of the plant’s growth cycle, so if you harvest the plant too soon, you will end up with small flowers. But that doesn’t mean you let your flowers grow until the last day — such flowers may not be so potent or flavorful. 

You need to harvest the flowers at the right time when they have grown fat but still not compromised their terpenes and cannabinoids. 

The best way to know when your buds are ready for harvest is when some trichomes appear cloudy or white and others appear amber. Wait for some days if the trichomes are still clear, but don’t wait until all the trichomes turn amber. 

Summary: How to Grow Fat Cannabis Buds: 8 Tips to Increase The Bud Size

If you grow cannabis under the right circumstances, you already have a good chance of growing fat buds. But that doesn’t always happen. By being a little more careful with the growing environment, using the right nutrients at the right time along with supplements, and training the plant well, your plant is bound to grow fatter buds.

Hopefully, the tips mentioned in this guide will help your cannabis plant reach its potential and grow fat flowers unlike ever before. And if you have some tips that have worked for you in the past, do let us know below.


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