Creating the right temperature for a cannabis plant is one part art, another science, and another, well, common sense.
As a ganja farmer, temperature and humidity are things of concern to your grow process.
It is as important as choosing the material for growing your plants, the strains of cannabis seeds you decide to plant, the lights, the watering systems, and the nutritional requirements.
Armed with a hygrometer and a thermometer, you can accurately keep track of your grow operations’ humidity and temperature levels.
Let’s explore the best temperatures for a marijuana plant.
Importance of temperature to a cannabis plant
Temperature is directly related to the life span and yield of cannabis plants.
When growing weed indoors, if the temperature in your grow room is too low, your entire crop may wither.
If the temperature is too high, your plants will produce fewer flowers.
For photosynthesis (the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar) to happen, your cannabis plants need the right temperature.
The temperature of a plant’s location quickens or slows down the entire process of photosynthesis.
At optimal temperatures, some enzymes generate internal reactions stimulating photosynthesis.
Cannabis plants that grow in such temperatures are more advantageous since they are capable of photosynthesizing efficiently.
Something important to keep in mind is that hot surroundings offer a conducive breeding environment for pests and disease while mold thrives in colder temperatures.
Temperature and Humidity requirements in all stages of growth for a cannabis plant
Plants do best in a particular temperature range, much like human beings.
At the different stages of growth, marijuana plants need varying temperatures and humidity levels.
It is important to monitor the humidity and temperature through all the four stages of cannabis growing (seedling/clone, vegetation, flowering, and late flowering)—a digital thermometer and hydrometer come in handy.
Temperature & Humidity recommendation at seedling/clone stage of marijuana growth
Seedlings and young clones need high humidity levels between 65 and 70 percent because the root system is deficient, and humidity allows water absorption through the plant leaves.
At the early stage of a cannabis plant, the ideal temperature for marijuana is between 75 and 80 degrees Fahrenheit (24 – 27 degrees Celsius); anything higher than that is bad.
Temperature & Humidity recommendation at Vegetative stage of marijuana growth
The proper humidity of a cannabis plant at a vegetative stage is between 50 and 55 percent. Through the vegetative period, lower the humidity levels by five percent each week.
You can know when the humidity levels are too high by looking at the plant leaves; wet spots start forming.
Cannabis plants can at the vegetative stage tolerate higher temperatures.
The developed root system allows the plant to absorb more water that evaporates through the plant’s leaves, cooling the plant.
Keep temperatures at the vegetative stage between 75 to 80 degrees Fahrenheit (24 – 27 degrees Celsius).
Temperature & Humidity recommendation Flowering stage of marijuana growth
Humidity levels at the flowering stage of a cannabis plant need to range between 40 and 50 percent.
It is important to note that the humidity levels should never exceed 60 percent.
Mold and mildew form and start infecting the plant from the inside if the humidity levels are high.
Marijuana plants need a cool temperature when they start budding.
Temperature for flowering around 65-80 degrees Fahrenheit (18-26 degrees Celsius) is optimal.
The correct temperature is vital at this stage to ensure your buds develop the best terpene content.
A cannabis plant terpene affects the color of the buds, aromas, and flavors.
Temperature & Humidity recommendation at Late flowering stage of marijuana growth
At the late flowering stage (1-2 weeks before harvest), temperatures dictate the plant’s yield, flavor, and appearance.
At this stage, it’s best to drop humidity levels as low as 30 and 40 percent.
Temperatures should range between 70 and 80 degrees Fahrenheit (21-27 degrees Celsius).
The cannabis grow room light temperatures should range between 64 and 75 degrees Fahrenheit (18-24 degrees Celsius).
Techniques of regulating temperature and Humidity Levels
Maintaining the proper balance of humidity and temperature may seem complicated; to your consolation, many home growers feel your pain.
To simplify things, remember humidity depends on the temperature.
Humidity relates to how much water vapor is in the atmosphere.
That means the warmer the air, the higher the relative humidity.
How to lower temperature and humidity
Increase the fresh, cool air supply in your growing area. A fan aids in circulating the warm air; in this way, all the plants receive equally, particularly in large spaces.
The proper watering of the plants when the lights are turned on abets the immediate absorption resulting in less overall humidity.
You can also use a dehumidifier to regulate humidity in the growing area.
To increase the temperature of your grow room, conventional heating sources work, including gas, electricity, and almost any kind of heater commonly used in our day-to-day lives.
Likewise consider heat lamps and insulation.
For warming the soil, heating mats are placed underneath the tent or grow room. You can also upgrade to a bigger grow light.
Grow lights are a good substitution for the high summer temps outside; they emit heat. They are the best alternative to grow and flourish plants in indoor grow rooms in any climate.
Grow lights mimic natural light, quickening photosynthesis which fuels the plant-grow life.
If the heat from the grow lights is intense, use lights that emit less heat or opt for fans or portable air conditioners to generate the proper temperature for your grow room.
Regarding Humidity, it depends on what stage of growth the plant is in.
Overall, pot plants have their most favorable outcome with a relative humidity between 40 and 70 percent.
In an event where conditions are too humid or too dry, the outcome is disastrous. In this case, your plants are susceptible to disease or mold or have fungus; in addition to that, the growth of your pot plants is retarded in very dry conditions.
Ways to Increase the Humidity levels
- Maintain moisture in the soil surface
- Using moist towels, edge the room and open containers of water
- Use a dehumidifier with a large water reservoir to constantly add moisture to the room.
- A hygrometer and humidifiers, dehumidifiers, and water systems support humidity regulation in a grow room.
- An additional way you can adjust humidity is by opening and closing the entrance of your grow room based on the conditions outside.
Wrap on Recommended Marijuana Temperature and Humidity levels
Temperature and humidity levels go hand in hand.
When growing cannabis, you must understand the humidity and temperature needs of the plant through its growth cycle.
All through the stages of growth, the continuous demand for water will vary with the humidity.
Less water is drawn from the roots at peak humidity levels since the plants utilize the moisture from the air through their leaves.
However, when humidity is low, there is more intake of water through their roots.
If you yearn for strong, healthy, nutrient-dense leafy plants, always keep track of the temperature and humidity levels of your grow room to prevent bud mold or rot, white powder mildew, nutrient deficiencies, and retarded growth.