It can be tough on the quest to find the perfect thermometer/humidity monitor, especially if you don’t want to spend a pretty penny. I like this one. It only costs $8, and it comes with a probe. I have the probe hanging in my grow tent near the plants, with the screen outside the tent. This setup makes it easy to see the temperature and humidity exactly where the plants are without having to open the tent.
Other fluorescent lighting uses very similar technology as CFLs, but the bulbs come in different shapes, some of which can be more suitable for growing. While not as stealthy or small as CFLs, other fluorescent lighting can be a cheap and effective way to nurture young cannabis plants.
7 Essential Concepts About Temperature Control
In general, you should strive to keep temps under 80°F (26°C) throughout the flowering stage, and especially towards the crucial second half when buds are in the midst of development.
Give plants colder temperatures at night, especially towards the end of the flowering stage
What else is affected by the temperature in the grow room?
Temperature & Humidity Adjustment Cheat Sheet
Learn more details below…
Please note temps above 80°F (26°C) in the flowering stage will slow down bud growth and may cause them to become airy and loose. The heat can also reduce the potency and smell of your buds. Keeping the grow room temperature under control is especially important in the flowering/budding stage!
In general, a sign of heat stress in marijuana plants are curling leaves. Here are some other signs to look out for:
About Too Hot for Pot?
During the vegetative stage, marijuana plants thrive in temperatures between 70-85 degrees Fahrenheit (20-30ºC). This is also the maximum temperature for marijuana grow tent use.
Soil is essential from the very beginning of a marijuana plant’s life. Marijuana seed germination is triggered when soil temperature, light, and moisture work together. For the best environment for your plants, consider investing in a soil thermometer to measure its temperature. The soil temperature should be maintained at 80ºF. This ensures that the roots stay warm. It also helps the stems and leaves withstand bouts of colder air (if you’re in an area that gets cool air). You can also place heat mats on the floor to maintain the soil temperature if your plants are not getting enough heat.