Environmental factors such as temperature have strong effects on cannabis growth. Canadian scientists showed that temperature regulates photosynthesis, water use efficiency, and other crucial processes in the plant. Cannabis is very sensitive to temperature fluctuations and may suffer from excess heat or cold. Therefore, maintaining the best temperature to grow marijuana is critical for sustaining healthy and fast growth.
Cannabis Temperature Requirements
Recommended marijuana temperature range is approximately 68-85 degrees Fahrenheit. The vegetative stage requires temperatures ranging from 68 to 77 degrees, while flowering is best in warmer conditions (65 to 85 degrees). The temperature may decrease by about 10 degrees at night. In other words, your indoor environment should mimic natural temperature increases in summer as your plants grow bigger.
Extreme temperatures have a severe adverse effect on cannabis plants. If it is too hot in the growing site, cannabis suffers from heat stress. Researchers explain that this condition alters plant metabolism, physiology, and cannabinoids production. Symptoms of heat stress include:
- Stunted growth
- Poor branch structure
- Poor flower quality (loose and airy)
- Bleaches and burns on the leaves (if the light source is located too close to the containers)
Similarly, cannabis is very vulnerable to cold temperatures. Sudden temperature drops can kill your harvest in one night. Hence, maintaining the optimal temperature range is your number one task. You are probably wondering, what is the lowest temperature a weed plant can survive? It all depends on the strain and plant strength, but temperatures dropping to 53 degrees and lower are life-threatening for cannabis. When cannabis suffers from cold, its metabolism slows down, hindering development and flowering. It means that you should never leave your plants in a cold garage or any other space unprotected from temperature fluctuations at night. Cannabis is more robust than you may think, but repeated temperature fluctuations could eventually kill it or decrease yield.
How to Measure?
We recommend using advanced analog thermometers. Hydrometers are also a good choice, as they measure temperature and humidity, allowing you to control these two significant parameters. They are also more accurate than analog thermometers and offer many additional functions. Thermometers are not expensive, so you don’t have to spend a fortune on temperature control. For accurate results, place the thermometer or hydrometer far from direct light. Light hitting the instrument raises the temperature, thus giving you a false reading.
Setting the Right Temperature
Now, it’s time to discuss setting the perfect cannabis growing temperature. If you need to make the growing site warmer, use the following:
- Gas or electric heaters
- Heat lamps
- Heat mats underneath pots
- Grow lights
However, don’t forget that heating the place is expensive, so choose energy-efficient devices.
Conversely, if the growing site is too hot, switch the air conditioner on or open the growing site for a while. Fresh air will cool it down, creating a more favorable atmosphere for plant growth. Since growing lights increase the temperature, you may need to choose those emitting less heat.
The harvesting stage also requires attention to the room temperature. Drying occurs between 65-75 degrees, while higher temperatures may cause cannabinoids, terpenes, and flavonoids to evaporate. As a result, your buds’ flavor, scent, and effect will suffer. Therefore, don’t be misled by the seeming flourishing of your cannabis garden. Keep maintaining the needed temperature even after the harvest is ready. As for the curing, a cheap thermometer will allow you to find a dark, cool space somewhere in the cupboard, with temperatures ranging between 60-70 degrees.
Don’t forget that cannabis watering temperature is also critical. Colder water hinders moisture and nutrient intake from the soil. Cannabis grows best if you regularly supply it with 68-71 degrees water.
Temperature control may seem overwhelming, but once you master this art, you will notice enormous improvements in cannabis growth. Ensure you measure the temperature regularly and adjust the environmental conditions as needed.