Growing cannabis can be a challenging but rewarding experience for any enthusiast. Whether you are a seasoned grower or just starting out, there are many factors that contribute to the success of your plants. One important factor that’s often overlooked is ventilation and airflow. In this post, we will explore the importance of ventilation and airflow when growing cannabis, and how to encourage proper ventilation and airflow in your grow room or outdoor garden.
How Do Cannabis Plants Breathe?
First, let’s learn the basics by asking the question “how do plants breathe?”
Plants breathe just like animals do, except a little differently. Plants take in carbon dioxide from the air through small openings on the bottom of their leaves called stomata. CO2 is used in the process of photosynthesis, where is combined with water and sunlight to make food for the plant. The plant then releases oxygen and glucose as a result of photosynthesis.
Keeping those three things (CO2, water, and sunlight) plentiful is the job of that cannabis grower. When the plant has plenty of all three it can then feed on nutrients and grow quickly.
Temperature, Humidity, and A Breath of Fresh Air
It is very important to understand airflow when growing cannabis. Cannabis plants need a steady flow of fresh air to thrive. Airflow helps to prevent pests and diseases, as well as to provide your plants with the necessary carbon dioxide to grow. Poor airflow can lead to stagnant air, which can lead to problems like slow growth and bud rot.
Plants have no way of moving air around themselves. As the leaves absorb carbon dioxide and create oxygen, there’s nowhere for this oxygen to go. What can happen without proper airflow is that the immediate area around the leaves becomes rich in oxygen, essential suffocating the plant.
Airflow is important for both indoor and outdoor cannabis plants. There needs to be an almost constant flow of CO2 rich air around your plants so they can breathe efficiently.
Airflow also helps regulate the temperature and humidity around your plants.
High humidity levels can lead to mold and mildew growth, which can ruin your entire crop. If the temperature around your plants is too high or too low, it can negatively impact growth and development.
Outdoor Cannabis Airflow
A common problem with outdoor cannabis plants is a lack of airflow and humid air trapped within the plant’s canopy. This is especially a problem with bushy weed plants. Unchecked, this can lead to powdery mildew and bud rot and is especially a problem with bushy plants. When the temperature outdoors is cool, water condenses out of the air and you get dew. In a bushy plant, this cool humid air has nowhere to go and condenses on the plant. Sometimes this moisture will get trapped in a bud or node and lead to mold growth (bud rot).
We can mitigate these issues by pruning our outdoor plants a few times during their life cycle. Simply remove a few lower branches and leaves with a pair of clean scissors. Choose leaves and branches that don’t get a lot of light since they aren’t providing much energy anyway.
Once you remove this excess plant material, air can freely move through your plant eliminating high humidity spots and exchanging O2-rich air with fresh CO2-rich air the plants can breathe.
Indoor Cannabis Airflow
There are many different types of indoor ventilation systems available for cannabis cultivation of all scopes. The most common pieces of equipment grow masters use for airflow are exhaust fans, intake fans, and carbon filters. Exhaust fans help to remove stale air and humidity from your grow room, while intake fans bring in fresh air. Carbon filters are used to remove any unwanted odors from your grow room. It is important to choose the right type of ventilation and airflow system for your grow room, based on the size of your space and the number of plants you are growing. As you can imagine, you will need to be able to move more air in larger growing spaces.
Most hobby growers will have a basic grow tent setup. It’s a much smaller scale than commercial growers but the same considerations apply. In a small indoor tent, you can usually omit the intake fan. An exhaust fan will be able to create a negative pressure inside your tent that will suck in fresh air from the vents on the tent. Since it’s inside the house you live in, there should be plenty of CO2-rich air for the plants to breathe.
Your exhaust fan should be set up so that it is sucking air through your carbon filter and sending it to another room in your house or outside.
An exhaust fan will replenish the air inside your tent but it doesn’t do the best job at circulating air inside the tent and eliminating hot or humid spots. An oscillating fan is an important piece of equipment that should be in every indoor growing environment.
The fan will help move air around the stomata making it easier for the plants to breathe. The fan will also move air around the tent and reduce the hot spots that tend to develop just above the canopy where the light hits the plant.
Some ventilation systems are controlled by a thermostat but there can be a problem with these systems. Your plants need constant airflow. You want to keep the air circulating. When using an inline fan with a thermostat you want it to speed up when it’s too hot in the tent and slow down when the temperature is low. Some thermostats will shut off completely when the temperature is low, this isn’t ideal. If you’re looking at a more automated ventilation system, please take this into consideration when making your choice.
Properly setting up and maintaining a ventilation and airflow system is crucial for the success of your cannabis crop. It is important to regularly check and adjust your ventilation and airflow system to ensure that it is working properly. This includes monitoring the temperature and humidity levels in your grow room. It is also important to regularly clean and replace your carbon filters to ensure that they are working efficiently.
You can tell when a carbon filter is getting old or not working correctly when you start to smell your flowering weed plants outside the tent.
To sum it all up; proper ventilation and airflow help to control temperature and humidity levels, as well as helping plants breathe freely. Circulate the air in your grow room and your outdoor garden by pruning plants. It is important to invest in proper ventilation and airflow systems and to properly set up and maintain it to ensure the success of your indoor cannabis crop. Remember, a little bit of effort goes a long way in getting the best yield and quality of cannabis. Happy growing!
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