As a beginner in greenhouse gardening, you might be asking, “How hot can a greenhouse get?” Directly put, a greenhouse can reach temperatures up to 100°F and sometimes even beyond.
In this article, we’ll provide a deeper understanding of greenhouse temperatures, discuss the ideal temperature range for plant health, and offer practical strategies for temperature control. We’ll cover ventilation, shading, monitoring tools, and humidity management—essential topics for maintaining a healthy greenhouse environment. Let’s get started.
How Hot Can a Greenhouse Get?
Our extensive experience and research indicate that on a bright, sunny day, the unheated greenhouse temperature can soar to a sweltering 100°F or more. This intense heat, akin to a midsummer’s day in the tropics, can create an environment that might be too harsh for many plants.
But why are greenhouses warm? The science behind this heat spike is simple yet fascinating. A greenhouse traps sunlight, converting it into heat that warms the air, soil, and plants within.
This is the greenhouse effect at work, an invaluable principle for growing but one that requires careful management. Without proper temperature control, this miniature ecosystem can quickly become a stifling desert rather than a nurturing haven.
It’s not just the air temperature that rises; surfaces inside the greenhouse absorb heat and can become hot to the touch, further elevating the ambient temperature.
This can lead to a phenomenon known as ‘leaf scorch,’ where the plant leaves get burnt, turning brown and crispy at the edges. Tender seedlings and delicate plants are particularly vulnerable to these sauna-like conditions.
Therefore, while the capability of a greenhouse to reach such high temperatures is impressive, it underscores the importance of monitoring and managing the heat to protect your plants. In the following sections, we’ll explore how to maintain the delicate balance needed to leverage the warmth without endangering your greenery.
What Is the Ideal Temperature for a Greenhouse?
Now, while greenhouses can get pretty toasty, the minimum greenhouse temperature range for optimal plant growth is around 60-75°F. Maintaining this temperature ensures a good harvest, more production, and of course, happy plants.
But why this particular range, you ask? Well, it’s all about balance. At cooler temperatures, plants slow down and conserve energy, which can be great for some, but not when you’re aiming for growth.
On the flip side, when the thermometer pushes past 75°F, many plants start to stress out. Their pores, or stomata, open wide to release excess heat, and in the process, they can lose too much water, leading to dehydration.
Keeping your greenhouse within this ideal temperature bracket is a bit of an art and a science. It’s where your veggies will plump up nicely, your flowers will bloom vividly, and your fruits will sweeten up just right. Plus, it’s a comfortable range for you to work in, too. After all, if you’re breaking a sweat, chances are your plants are feeling the heat as well.
So, as we delve into the how-tos of temperature control, remember that maintaining this ideal range is the key to a vibrant, productive greenhouse. It’s not just about avoiding the extremes but providing a consistent, optimal climate where your plants can thrive day in and day out.
How to Control the Temperature of Your Greenhouse
Ventilation is key
If you’re wondering how to cool a greenhouse without electricity, then ventilation is one of the best ways to do this. Unlocking the doors and windows or having roof vents can significantly help in cooling down your greenhouse. Proper ventilation ensures that fresh air circulates, preventing the buildup of excessive heat and allowing for better temperature control.
Utilize shading techniques
Shading is your greenhouse’s best friend when the sun is relentless. Using shading paints or blinds can significantly reduce the temperature inside. After trying them ourselves, we’ve found that blinds are particularly effective as they block the sun before it penetrates the glass, keeping the interior from overheating.
On cooler days, these can be easily removed to let in more light. For a more budget-friendly option, mesh and nets can serve as an alternative to blinds, but make sure they are securely attached to provide consistent shade.
And if you’re in a warmer environment, you might be wondering, can a greenhouse be in partial shade? As long as your plants are getting at least 6 hours of sunlight, then yes, it can.
Invest in tools
From our experience, having a thermometer inside the greenhouse is a must. It allows you to monitor the temperature and make necessary adjustments. Automatic vent openers and fans can also be beneficial. They not only help in temperature regulation but also prevent the spread of diseases in stagnant air conditions.
Dampen the greenhouse
During extreme weather, dampening the greenhouse can increase humidity, helping plants withstand the heat. This method also deters pests that thrive in dry conditions. However, ensure you don’t overwater.
Use automatic vent openers
Sometimes, the best solutions are those that work seamlessly in the background. An automatic vent opener is a non-electric device that responds to temperature changes by expanding a piston that opens the vent.
This smart tool ensures that even when you’re not around, your greenhouse can breathe, releasing hot air and maintaining a more stable temperature. It’s a set-and-forget solution that can make a significant difference in the daily temperature fluctuations within your greenhouse.
