Photosynthesis In Marijuana Plants

So, what is photosynthesis and how does it affect marijuana plant growth? Your cannabis plant requires energy just like we do, so we are going to explore how your plant gets its energy and the role you play in this.

Photosynthesis is an essential process for plant growth and all plants naturally do this. There is no getting around this. Plants have the ability to take in light through its leaves and efficiently transforms this usable light into energy. Marijuana plants have an ample amount of chlorophyll which is how it absorbs light.

What is photosynthesis

What is photosynthesis in cannabis

The more leaves your cannabis plant has, the more light energy it is able to receive, therefore it will be a greater powerhouse generating more energy. The thing is your plants don’t just take any source of light. A certain type of light is necessary. The strength and specific color of the light matters for photosynthesis to take place accurately. For instance, blue light is necessary during the growth process and once it is time to start blooming, your plant needs red and orange light. There are unique lamps that exist just for this purpose. Read more in the article Best marijuana grow lights

Converting light into energy also requires the usage of carbon dioxide (CO2) from the atmosphere and water (H2O) from the soil. As the plant receives energy, it is gathered in chemical compounds such as nicotinamide-adenine-dinucleotide-phosphate (NADPH2) and adenosine-triphosphate (ATP).

NADPH2 plays a necessary role in synthesizing carbohydrates while ATP generates carbohydrates. These compounds are how energy is moved through different parts of the plant. Basically, light from ATP and NADPH2 combine with CO2 and H2O to form carbohydrates.

Creation of sugars

Photosynthesis in cannabis the creation of sugars

Chlorophyll plays a role in giving the plant the energy needed to convert CO2 and water into sugar during daylight hours. The left over oxygen is a waste product for the plant and is released through the leaves. This process is the consumption of carbon dioxide.

The water contains an unlimited supply of nutrition. The more abundance of energy the better cannabis plants will grow. During the night is when the production of protein occurs. So, at this time the sugar and oxygen are transformed into CO2 and water vapor. This is what we call the breathing of the plant. Cannabis plants use this energy for creating proteins that do not generate during the assimilation at daylight.

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Your plant is going to use the carbohydrates it created as a source of food and nourishment. The sugar created by carbohydrates mix together creating cellulose which makes up about 4/5 of the plants cellular structure. One of the more essential compounds on planet earth is cellulose and photosynthesis plays a large role in it being generated in cannabis plants.


co2 photosynthesis marijuana

The higher the amount of carbon dioxide means better plant growth. While CO2 is a naturally occurring gas, you can always add more to the space where you are growing your plants. Because of how photosynthesis works, the more light you have the more vibrant your plant will grow. The more CO2 and light energy your plant gets, it will automatically create more carbohydrates which lead to greater cellulose production.

Please keep in mind that unless you use a hydroponic system, things work completely different when it comes to water. Water is important for your plant to live and flourish, but it must be used in a balanced way. Consistently pouring water on a cannabis plant will flood the roots of your plant. This would be counterproductive and could potentially kill your baby.

The roots of you plant require oxygen in order for it to breathe. If your plant is engulfed in water, it will not allow the soil to make space for oxygen to mix in. You will find that your plant will start deteriorating quickly due to this.

Day and night

Day and night photosynthesis in marijuana

It is important to understand why both day and night periods are necessary. When your plant is in its growth stage, you will want to make the daylight hours longer than night. You do have total authority over this. The growth period is when it is okay to blast your plant with tons of light. You will be giving it daylight time like what it would naturally experience during the summer months. For the best results, an 18-hour daylight period is actually all that your plant needs. This growth stage last approximately 3-4 weeks.

However, your plants flowering period only requires 12 hours of daylight. In this way, it is echoing the fall season. The flowering stage is when your plant needs to rest and build up its strength. Your baby will need room to grow naturally. So, 24 hour light blasting is way too much. More than 12 hours of light could potentially cause your plant to re-enter the growth stage and you don’t want to mess up the natural cycle your plant needs to go through.

During the flowering stage, you will want to create your own version of sunrise and sundown. So again you are reducing your plants exposure to light down to only 12 hours per day. This way your marijuana plant can experience complete darkness. All lights will have to be turned on so your plant can get some sleep. This is the best and more natural way for your cannabis plant to grow at its maximum potential.

You might be surprised at how much growth your plant can get during the flowering stage. The growth can be as much as two to three times its size. At this point, your cannabis plant no longer needs to store nutrients. It is ready to start growing into an adult, flowering full force now.

As mentioned earlier in the article, different types of lighting is necessary at various stages of your plants life cycle. The growth stage is when cannabis plants require a blue spectrum light, which lasts close to one month. The blue lighting can be used during this time as much as 24 hours daily because more light is beneficial during the growth period. Now, when it is time for your plant to start the flowering stage, you will switch from blue light to red. The red lighting is necessary until the cannabis plant is about to produce the first bud.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible


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Robert Bergman


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

10 comments on “Photosynthesis In Marijuana Plants”

  1. You mention in the flowering stages that 12 hours of complete darkness is needed. In the very next sentence “All lights will have to be turned on so your plant can get some sleep”…Small oversight 😉