How to cool your greenhouse or polytunnel in summer

As the summer heat peaks, keeping your greenhouse or polytunnel cool becomes a priority for any gardener. Uncontrolled temperatures can stress plants, hinder growth, and even cause damage. At Harvst, we specialise in gardening automation systems, including our innovative WaterMate automatic irrigation solutions, designed to help you manage your garden effortlessly. You can utilise solar power for watering off-grid, or take advantage of all of our options with the mains powered versions– connect all your Harvst tech gadgets to one centralised (and automated) system. In this blog, we’ll explore effective greenhouse cooling tips and polytunnel temperature control ideas during the hottest time of the year.

Ventilation: Let the Air Flow

Proper ventilation is crucial in maintaining a stable temperature in your greenhouse. By allowing hot air to escape and cooler air to enter, you can significantly reduce the internal temperature.

– Automatic Vent Openers: Investing in automatic vent openers is a great way to ensure your greenhouse is well-ventilated without manual intervention. These openers use a temperature-sensitive mechanism to open and close vents as needed, keeping your plants cool and comfortable. Our Automatic lid lifters work by the heating and cooling of wax inside to lift your greenhouse window when temperatures soar. No power needed!

– Fans and Circulation: For larger structures, installing oscillating fans can help improve air circulation, preventing hot spots and ensuring uniform temperature distribution.

Shade Cloth: A Simple Yet Effective Solution

Shade cloths are an excellent way to reduce the amount of direct sunlight entering your greenhouse. They come in various densities, allowing you to control the amount of light and heat.

– External vs. Internal: External shade cloths are more effective at blocking heat before it enters the greenhouse. Internal options are easier to install but may trap some heat inside.

– Automated Shade Systems: Consider an automated shade system for optimal convenience. These systems can be programmed to deploy the shade cloth based on temperature or time of day, offering protection when it’s needed most.

Damping Down: Humidity to the Rescue

Increasing humidity through damping down can help lower the temperature in your greenhouse. This process involves wetting hard surfaces like paths and shelves, which then evaporate and cool the air. To have accurate measurements of the humidity level in your greenhouse, Harvst has a Wireless humidity/temperature sensor that can connect to your WaterMate.

– Automatic Misting Systems: To make damping down hassle-free, consider installing an automatic misting system. These systems can be set to mist at specific intervals, maintaining ideal humidity levels and cooling your greenhouse without constant oversight. Our WaterMate can be used to help mist your greenhouse or polytunnel and paired with our humidity sensor, your system will automatically turn on when humidity gets too low or the temperature gets too high. Until the end of August 2024, use code ENVCONTROL to get a free humidity sensor with your WaterMate!

Watering Wisely: The Role of Automatic Irrigation Systems

Proper watering is essential for keeping plants healthy, especially during hot weather. Harvst’s WaterMate automatic irrigation systems can take the guesswork out of watering, ensuring your plants receive the right amount of moisture.

– Timing and Frequency: During hot weather, watering in the early morning or late afternoon can help minimise water loss due to evaporation. Our systems can be programmed to water at the optimal times, ensuring efficient water usage.

– Soil Moisture Sensors (coming soon): For even more precision, integrate soil moisture sensors with your irrigation system. These sensors monitor soil moisture levels and adjust watering schedules accordingly, providing your plants with exactly what they need.

Reflective Mulch: A Double Benefit

Reflective mulch, such as white plastic or aluminium foil, can help keep your greenhouse cool by reflecting sunlight away from the soil and plants. This not only reduces heat but also helps retain soil moisture and conserves water.

Cooling your greenhouse or polytunnel in summer doesn’t have to be a daunting task. With the right tools and strategies, such as automatic vent openers, shade cloth, misting systems, and Harvst’s automatic irrigation systems, you can create a comfortable environment for your plants to thrive. Whether you’re a hobby gardener or a commercial grower, these solutions will help you maintain optimal conditions and ensure a bountiful harvest.