How Temperature Affects Indoor Growing

Stable grow room temperatures result in strong, healthy, vigorous plant growth. Temperatures that are too high or too low prevent healthy growth, cause foliage damage, leaf drop, and plant failure. This blog helps you stop excessive temperature fluctuations, protect your plants, and boost your yields!

What Plant Processes are Affected by Grow Room Temperature?

Temperature is a critical factor in plant life cycles, influencing germination, vegetative growth, flowering, and fruiting. Optimal temperatures ensure healthy development and maximise yields. Here’s a detailed breakdown of the processes affected by grow room temperatures:

• Photosynthesis: Grow room temperatures influence the rate of photosynthesis. Optimal temperatures allow for efficient conversion of light into energy for growth at every stage.
• Respiration: Respiration is the opposite of photosynthesis, where plants release energy from stored sugars. Higher grow room temperatures cause excessive respiration, depleting energy reserves.
• Transpiration: Grow room temperatures affect transpiration (sweating), the process of moving water throughout the plant and its evaporation from the leaves. Higher temperatures increase transpiration, leading to nutrient burn.
• Nutrient Uptake: Grow room temperatures affect your plants’ ability to absorb nutrients. Low temperatures prevent plants from absorbing nutrients efficiently. High temperatures hinder nutrient uptake, causing nutrient “lock-out”.

What is an Ideal Temperature Level for my Indoor Plants?

Your indoor plants need different temperatures depending on the time of day and their stage of growth. Here are some general guidelines for each stage of growth:

• Seedling Stage:
  • Daytime Temperatures: Young plants prefer daytime temperatures between 20–25°C.
  • Nighttime Temperatures: Reduce grow room temperatures to 17–22°C at night, during the light-off period.
• Vegetative Stage:
  • Daytime Temperatures: Plants which are developing foliage and young bud sites need grow room temperatures between 22–28°C to encourage vigorous growth.
  • Nighttime Temperatures: This temperature range should reduce to between 18–20°C during the light-off period.
• Flowering Stage:
  • Daytime Temperatures: Bud sites, flowers, and fruit develop best in grow room temperatures ranging between 20–26°C.
  • Nighttime Temperatures: This temperature range should be reduced to between 18–22°C during the light-off period.
• General Rules for Nighttime Temperatures:
  • Temperatures should be 5–7°C cooler than daytime temperatures.
  • This temperature difference prevents leaf burning, oversaturation, and other plant stressors.
  • It mimics natural conditions, promoting healthy circadian rhythm and efficient nutrient use.

How Do I Control Temperature in my Grow Room?

There are several ways to control temperature using a combination of ventilation, air circulation, heaters, and air conditioners.

• Ventilation: Intake/outtake fans, ducting, and filters work together to create a good ventilation system. This equipment regulates grow room temperatures by exchanging hot, stale air with fresh air. Our range of fans and filters optimise airflow and humidity management.
  • High-Performance Fans: We offer a wide range of high-quality intake/outtake fans suitable for a variety of grow environments. Our fan range offer single, twin, and thermostatically controlled options, ensuring you get the perfect unit for your grow space.
  • Unrivalled Air Quality Control: Our filters are specially selected for their ability to remove odours and volatile organic compounds from the harshest grow environments.
  • Fantastic Choice: Global Air Supplies stocks only the best, most trusted brands on the market. With a wide variety of fans and filters to choose from, optimised plant health and high-quality yields are guaranteed no matter which unit you use.
• Air Circulation: Circulation fans prevent hot spots created by heat-generating equipment such as grow lights and heaters. Moving air maintains optimal temperature and humidity levels in the grow room by redistributing heat, preventing stagnant air build-up.
  • ora Circulation Fans: Circulation fans by ora are high-quality yet budget friendly solutions for balanced air movement, temperature control, and pathogen prevention.
• Heaters: Heaters prevent sudden temperature dips which damage delicate plants and impact growth. They are especially important for controlling temperature in outdoor grow spaces, such as poly tunnels. There are several ways to increase temperatures depending on your plants’ growth stage.
  • Heated Propagation: Heated propagators by Vitopod and X-Stream evenly distribute heat to boost young plant growth.
  • Vegetative Growth & Flowering: For later growth stages, we recommend the 2kw Fan Heater or Tube Heater by ora to prevent cold spots throughout every level of the canopy.
• Temperature & Humidity Control: Equipment must respond quickly to environmental changes to protect your plants’ health.
  • 24-Hour Environmental Control: G.A.S’ Intelligent Humidity Controller (IHC) Dual affords different day and night settings for your humidifier and dehumidifier units. Probes continuously monitor humidity levels in your space, making real-time adjustments to maintain your chosen humidity setting.
  • Grow Light Optimisation: Coupled with the DLI Digital Controller DLM-4 Zone, growers get ultimate environmental control. This controller automatically adjusts light outputs in response to temperature fluctuations, preventing heat stress and oversaturation. These controllers give you peace of mind that your plants have a perfect growing environment, even when you’re not there.

Now you understand the basics of grow room temperature control! Ensure healthy plant growth, prevent disease, and optimise yields with your next grow. Check out the Global Air Supplies website for our range of high-performance ventilation and temperature control equipment. Or, read our latest blogs to learn how to create the perfect environment for your plants to thrive.