How To Cool A Greenhouse [The Ultimate Guide 2024]

A greenhouse is designed to protect the off-seasoned plants from excessive heat and cold. It requires full sun but not overheating the greenhouse. Overheating can increase the presence of insects, reduce crop quality, and lower yields. On the other side, some of the plants prosper well in excessively hot temperatures.

That’s why, in the summertime, maintaining the greenhouse temperature is very critical. As the heat builds, it is essential to balance the coolness of a greenhouse. The growers use several methods for cooling down the greenhouse temperature. For your benefit, we will provide some techniques for how to cool a greenhouse.

What Temperature Is Too Hot for a Greenhouse?

A too hot-tempered greenhouse can damage all your crops. Above 90°F is considered the most excessive temperature for a greenhouse. That can decrease the plant’s production and minimize the growing season. 80°F to 85°F is the ideal temperature for most plants to flourish.

The ideal greenhouse temperature differs from plant to plant. That is why you should know the ideal temperature range of your plants. Also, if they are heat-resistance or not.

Heat-Tolerant Plants:

Some crops can grow well in the heat. They can withstand a temperature of 80-90°F. Tomatoes, eggplant, cabbage, cucumbers, okra, chili pepper, sweet potatoes, beans, watermelon, etc., are the summer crops. However, 90­° is still hot for them; that’s why many people consider it the best 6×8 greenhouse polycarbonate.

Heat-Sensitive Plants:

You need to be very careful with heat-sensitive plants. These plants can survive under 75°-85°F temperature. Beets, arugula, collards, kale, onion, peas, pak choi, lettuce, cauliflower, brussels sprouts are the heat-sensitive plants. These plants require lower temperatures in the greenhouse for a successful harvest.

Always remember 90° is too hot for heat-resistant plants and 85° is excessively hot for heat-sensitive plants. So, make sure your greenhouse doesn’t cross these temperatures.

How to Cool a Greenhouse?

As we discussed above, the excessive temperature can cause damage to your greenhouse plants. Thus, we give some methods so that you can learn how to cool a greenhouse.

Ventilating a Greenhouse:

Proper ventilation and circulation of air are much needed for a greenhouse. Not only does ventilation provide fresh air, but they also control the heat and temperature. The greenhouse door, roof vents, side vents, and ventilation can create air movement to cool down the overheated plants.

The roof vent area should be equal to one-fifth of the floor. Thus, it can generate a proper air change every 2 minutes. Also, an open door and side vent can assure sufficient air movement. On sunny days, you can keep the doors and vents open. You can apply this method for warm nights also. To protect the plants from pets and animals, make sure to tie a net over the door.


The most cost-effective and quick way to cool down the greenhouse is by providing shade. Firstly go with nature; for example, you can select plants with larger leaves. They can provide shade to the soil and keep the greenhouse cooler. Secondly, use shade curtains or shade cloths to reduce the sunlight heat. Fortunately, it can minimize the heat by 50 %. You can use shades both internally or externally.

Curtain systems come with several designs like gutter to gutter, truss to truss, and the two-screen system. Gutter to the gutter system comes in a bulkier form. The truss system is very popular among gardeners. Because it can effectively reduce the cold area of the greenhouse. The two-screen system is a combination of a light deprivation screen and a climate screen. With this system, growers can control the greenhouse temperature easily.

Damping Down and Circulation:

On a hot summer day, there is nothing better than dumping down to cool the plants. This process makes the inside of the greenhouse humid by wetting the hard surface. When the water evaporates, the moisture level of the greenhouse air increases. This thing helps the plants to cope up with the heat. The best thing about raising humidity is, it makes the greenhouse unfavorable for pests.

Electric fans are a must for keeping proper air movement and temperature consistency. In the greenhouse, these fans help to cool the air surface by pushing the warm air out.

You can try some other procedures to decrease the temperature of the greenhouse. Such as geothermal heating and chillers, evaporation, water tank, and transpiration.

Frequently Asked Questions

This section will show you more clarification about Greenhouse. Have a look and learn about the greenhouse temperature.

Do I Need a Fan in My Greenhouse?

Yes, because an exhaust fan can keep the greenhouse cool by improving temperature regulation. It can constantly supply fresh air, keep all kinds of pests out, and allow plant pollination or reproduction.

Should Greenhouses Be in Full Sun?

Yes, the greenhouse needs full sun to improve the plant’s health. Per day it should get 6 hours of proper sun. You should avoid shadows from buildings; that’s why try to site the greenhouse properly.

Can Greenhouse Be Too Hot?

As a greenhouse needs full sun, so it’s natural that it will get hot. But, anything above 90°F is considered too hot for the greenhouse. Too hot temperatures can damage all the plants.

Can You Use a Greenhouse in the Summer?

Yes, you can use a greenhouse in the summer. Using a greenhouse in the summertime, you can simply pick up those crops that will grow well with the sun. Also, by using sunshade, water and providing ventilation, you can use it.

Final Words

Owning a greenhouse comes with huge benefits as well as lots of challenges. You have to ensure proper heating and ventilation for keeping the ideal temperature for the greenhouse. Without a perfect temperature, all the plants will fade and damage.

Depending on the level of geographical location and humidity, the temperature can vary. Thus, you should apply the above methods for balancing out the greenhouse temperature. This article showed you how to cool a greenhouse. These methods can help you to maintain an ideal temperature for the greenhouse.

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