Environment, Climate & Stress
Temperature
Temperature is the measure of how warm or cool the growing environment is, and it strongly affects plant growth and health.
What Temperature Means in Cannabis Cultivation
Temperature refers to the level of heat present in a plant’s environment and is one of the most influential factors in plant physiology. In cannabis cultivation and horticulture, temperature directly affects metabolism, photosynthesis, water uptake, nutrient availability, and overall growth rate.
How Temperature Affects Plant Metabolism
Plants function within specific temperature ranges where biological processes operate efficiently. Enzymes (proteins that drive chemical reactions) work best within ideal temperature windows. When temperatures fall too low, metabolic activity slows; when temperatures rise too high, enzymes can become damaged, and plant stress increases.
Why Temperature Control Became Important in Indoor Growing
The importance of temperature control in agriculture became well understood during the development of controlled-environment growing in the 20th century, especially with the rise of greenhouses and indoor cultivation.
Optimal Temperature Ranges for Different Growth Stages
In cannabis growing, optimal temperatures typically range from 70–85°F (21–29°C) during the light period and slightly cooler at night. Seedlings and clones prefer warmer, more stable conditions, while flowering plants often benefit from slightly cooler temperatures to improve bud density and terpene retention.
How Temperature Interacts With Humidity and VPD
Temperature interacts closely with humidity and VPD (vapor pressure deficit), influencing how quickly plants transpire (release water through leaves). High temperatures combined with low humidity can cause excessive water loss, while cool temperatures with high humidity increase disease risk.
Common Temperature Stress Symptoms in Cannabis
Temperature stress symptoms in cannabis include slowed growth, leaf curling, wilting, discoloration, foxtailing, and reduced resin production. Extreme heat can cause heat stress and light stress, while cold temperatures may lead to nutrient uptake issues and purple coloration due to slowed phosphorus movement.
Maintaining Stable Air and Root-Zone Temperatures
Maintaining stable temperatures involves proper airflow, ventilation, insulation, and appropriate lighting distance. Monitoring both air and root-zone temperature is important, as cold roots can limit nutrient uptake even if air temperatures are ideal.
Why Temperature Control Is Essential for Yield and Quality
Temperature is closely related to plant stress, humidity, light intensity, transpiration, and environmental control. For cannabis growers, managing temperature is essential for maintaining healthy growth, preventing stress, and maximizing yield and quality.
Related terms:
Humidity, VPD, Heat Stress, Cold Stress, Transpiration, Environmental Control, Plant Stress, Airflow.
Stay informed as the site grows.
If you’d like to be notified when new glossary terms or educational resources are added, you can join the mailing list below.
We send emails occasionally and only when there’s something genuinely useful to share.