Monitoring the temperature of your cannabis plant’s leaf surface, or canopy temperature, is essential for achieving optimal growth and yields.
You see, many growers invest significantly in environmental controls.
However, they sometimes forget to optimize their temperature at the canopy level where it’s most important.
So where do you begin?
Our cultivation specialists recommend prioritizing your Vapor Pressure Deficit (VPD), which directly impacts transpiration rates and nutrient uptake.
Simply put, Vapor Pressure Deficit (VPD) is the difference between the amount of moisture in the air and how much moisture the air can hold when it is saturated.
Let’s Dive Deeper in VPD…
VPD is key to optimal CO2 assimilation by the plant…
And its important to understand that the majority of your plant’s biomass is created from carbon captured through photosynthesis, making VPD optimization in the room — and especially at the canopy level — one of the keystones of a successful grow.
If your Vapor Pressure Deficit (VPD) is too high, the air is too dry, and your plants will lose moisture rapidly from excessive transpiration. They’ll then close their stomata to converse what water’s left, resulting in…
- Nutrient Deficiencies
- Wilting
- Stunted Growth
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On the other hand…
If your VPD is too low, it means the air is too humid and your plants can’t transpire efficiently. This can result in waterlogging within the plant tissues, leading to…
- Mold and mildew growth
- Reduced nutrient uptake
- Slower growth and weaker structure
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Your average environmental monitoring system will regulate temperature and humidity based on grow room conditions. But this can potentially lead to overlooking more nuanced canopy-level factors like VPD.
To measure Vapor Pressure Deficit, you’d calculate the difference between the actual vapor pressure of the air and the saturation vapor pressure at a given temperature. However, you can use a VPD chart to simplify the process and get quick and accurate readings.
Follow this link to see our VPD chart guide.
Next, you want to consider that…
Different Types of Grow Lights Emit Varying Levels of Radiant Heat
…Which can significantly affect your canopy temperature.
For example, High-Pressure Sodium (HPS) lights generate a substantial amount of heat and can raise the temperature around the plant canopy more than LED lights. However, while LED lights are generally cooler, they can still contribute to localized heating.
So long as you account for these differences, you’ll be able to manage your grow environment successfully.
As a helpful starting point, refer to your manufacturer’s guidelines.
Most will provide you with recommendations for the optimal distance between your new lights and the canopy. Stick to these guidelines and you’ll help ensure your plants receive the light they need without experiencing heat stress, leading to healthier growth and heavier yields.
Next, let’s take a look at…
5 Techniques for Controlling Cannabis Leaf Surface Temperature
As a cannabis cultivator, you can employ various techniques to maintain a balanced microclimate around the canopy and ensure your plants can thrive.
Here are some effective methods:
- Fans and Air Circulation: Positioning fans to move air in the gap between the light and the canopy helps dissipate heat and maintain an even temperature distribution.
- Light Distance Adjustment: Adjusting the distance between the grow lights and the canopy based on manufacturer guidelines can prevent excessive radiant heat from impacting your plants.
- Humidifiers and Dehumidifiers: Using these devices helps control humidity levels, ensuring they stay within the optimal range for VPD.
- Environmental Control Systems: Automated systems that monitor and adjust temperature and humidity in real-time can provide precise control over the growing environment.
- Infrared Thermometers: Regularly checking leaf surface temperatures with an infrared thermometer ensures that the canopy is not experiencing heat stress.
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Employ these methods to ensure you’re effectively managing your cannabis’s leaf surface temperature, and you’ll promote optimal plant development and heavier yields come harvest.
You also want to…
Optimize Your PPFD
While we need to dial in your canopy’s environment, we also want to make sure you’re getting the optimal PPFD from your lighting.
And sometimes, it can be a balancing act to optimize both.
An critical measurement in cannabis cultivation, Photosynthetic Photon Flux Density (PPFD) shows how much light reaches the cannabis plant leaves. PPFD is measured in micromoles per square meter per second (μmol/m²/s) using a special light sensor called a quantum sensor or PAR meter.
To coax optimal growth from your plants, you need to provide the right amount of light without causing problems like:
- Slowed Photosynthesis: Too much light can stress your plants, making it harder for them to use CO2 efficiently.
- Unhealthy Water Use: High light levels can make plants lose water rapdily, leading to imbalances.
- Slowed Growth: Excessive light can slow down cannabis’s overall growth.
- Leaf Damage: Too much light can burn or bleach the leaves.
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The goal is always to find the right balance – giving plants enough light to thrive without causing harm.
The best way to optimize your light environment is to use a PPFD calculator. This way, your cannabis receives the right amount of light during each stage of its development.
And with a PPFD calculator, you can tailor your lighting setup to optimize photosynthesis, leading to…
- Increased yields
- Improved plant quality
- More efficient energy use
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And you can get the most from your lighting setup without jeopardizing the health of your plants.
Concluding Thoughts on Cannabis Leaf Temperature
As you can see, effectively managing leaf surface temperature and refining your lighting environment is essential for growing a crop you can be proud of.
Utilizing tools like a VPD chart and PPFD calculator ensures you’ve optimized conditions for robust growth and heavy yields. And incorporating techniques such as proper air circulation, light distance adjustment, and dialed-in environment controls helps promote the balanced environment your crop needs to thrive.
The bottom line that with careful monitoring and adjustment, you can achieve the high yields and superior crop quality you’re after.
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