How to Keep Greenhouse Cool in the Summer

When it comes to keeping plants happy and healthy, most greenhouse systems are designed to keep the area cool and keep it from getting too hot. However, this doesn’t work in the summer when the temperatures are high.

You probably won’t be happy with the way your plants are growing in a boiling hot greenhouse during the summer months. This is why we have put together a guide to help keep them cool and plant-friendly.

This article will give you a huge amount of knowledge about how to keep your greenhouse cool in the summer. It will also help you put together a plan of action to keep it that way.

Damping Down

Getting rid of the water that’s trapped in your greenhouse is a very economical way to cool down your plants. You just need to hose down the hard surfaces of your greenhouse and let the air evaporate.

Damping down the greenhouse is a great way to keep the air around it moist and prevent pests from getting into it. It also helps keep the plants hydrated.

The time of day that you choose to damp down your greenhouse is very important. Doing so too late in the day can cause your plants to become too hot and dehydrated.

The process of letting the air evaporate takes a bit of time, so it’s important to plan ahead and set a schedule when to damp down.

Creating Shade

The proper shade will help lower the temperature of your greenhouse, but it’s also important to consider how much light you should block out. Having the proper amount of light will also help your plants grow.

There are many types of garden shading techniques that are designed to work seamlessly with greenhouse setups.


Having external greenhouse coverings is much better than having internal ones. They prevent the hot air from entering the greenhouse and heating it up.

If you are considering getting external greenhouse blinds, make sure they are strong enough to withstand harsh winter winds. They should also be durable enough to prevent getting damaged during the winter.


Shades are purely for aesthetics. Today, most greenhouse owners go for the green ones as they are more natural and will provide a more verdant setting.


When it comes to choosing the material for external blinds, make sure that it is UV-protected to prevent them from getting damaged.

Shade Paint

Some greenhouses are white because of the shade paint that’s used to coat the glass. This technique aims to reflect the light from the outside of the greenhouse instead of letting it penetrate the glass.

There are a variety of types of paint that can be used on various surfaces. Some will leave you with a smooth finish, while others will require the removal of various tools.

The paint can be left on for up to a couple of weeks, which makes it ideal for keeping your greenhouse looking great all summer long.

Here’s how to paint your greenhouse step by step:

  1. Remove any dust and grime from the window.
  2. The glass should be completely dry.
  3. Coat the glass with paint using a radiator roller (you may use a paintbrush if you prefer, however, this will give a streaky appearance).
  4. Unless you want the glass to be fully opaque, one coat is typically plenty.
  5. At the conclusion of the summer, peel or wash the paint off.

When painting the greenhouse and wanting a unique style, stencils can be used to embellish it.

There are a couple of drawbacks to utilizing this shading method:

  1. Every summer, you’ll have to apply and remove the color at the beginning and conclusion of the season, which is a time-consuming operation.
  2. The paint is quite costly, especially if you plan on keeping your greenhouse for a long time.
  3. Once the paint is on the glass, you have no control over the heat or light within the greenhouse. On cloudier days, this can result in the plants receiving insufficient sunlight.

Shading Cloth

There is nothing like a good old fashioned shade cloth for your greenhouse. It’s a great way to save a few dollars and still maintain a beautiful greenhouse. A quality shade cloth can last up to 12 to 13 years.

Installing a shade cloth on your greenhouse is easy if you follow these basic steps:

  1. Measure your greenhouse’s length and width, as well as 14 or 13 percent of the way along the sides.
  2. Examine the plants in your greenhouse to see how much light they require. Vegetables, for example, require a lot of sunlight per day to develop. In this scenario, a shade cloth with a 30 percent shade will suffice. You may buy shade cloths that provide different amounts of shade, so knowing what your plants require will help you make the best decision.
  3. Purchase a shade cloth that is the same size as the one you measured. Just in case, you can add a few inches to the length.
  4. Cover the greenhouse’s roof with the shade cloth. Make sure the excess fabric hangs evenly on both sides.
  5. Attach the cloth to the greenhouse frame with staples. This will very certainly necessitate the use of a ladder. The material must be pulled taut between the staples with no gaps.
  6. Staple the top of the greenhouse all the way around, allowing about 15 inches between each staple.
  7. Make a hole in the excess hanging material at each corner. Poke a hole in the rim of the greenhouse at every meter of the fabric if it’s a big one.
  8. Each hole should be tied with a large piece of string that reaches the floor.
  9. Tie the string’s bottom end to a peg and drive the pegs into the earth. The side pieces of cloth will stay in place as a result of this.

Shade Netting

Similar to shade cloth, shade netting is made from a stronger material that prevents it from collapsing under the weight of a heavy snow. It can also be used in areas where heavy snow is expected.

When used for shade, shade nets can help reduce wind impact and protect plants from harmful UV rays. They can also be installed around fragile plants to keep them safe and shaded.

Unfortunately, there are a few drawbacks to using shade netting for shading. One of these is that it can only be used in three shades percentage options, which means that it can only provide you with a limited amount of shade. Also, it can obstruct vents, which can be dangerous to the plants.

Follow the instructions provided in the manual for the installation of a shade cloth. You can also use shade nets for a more permanent structure.

Good Ventilation

During times of the year when the wind is not powerful enough to upset the plants, you can use the ventilation ducts to keep the greenhouse running smoothly.

When the weather is mild and breezy, you can open the windows and let the natural air flow through your greenhouse. Unfortunately, this method will only work for a few weeks of the year.

Active Cooling

An active cooling system is a type of equipment that uses wind power to cool down a greenhouse. It needs to have a wind speed of at least 3 miles per hour to get the necessary airflow.

Active cooling systems are very expensive and are often used to cool a greenhouse. However, they are also required to install an electricity source in order to operate properly.

Aside from being practical, electrical tools can also help people control the heat in their greenhouse. This is especially beneficial if you want to keep the temperature exactly where you want it.


There are a lot of fans on the market, many of which are reasonably priced. Having a few fans around the greenhouse will help keep the air flowing.

If you have limited space, a ceiling fan may be the best choice for you. It can fit in wherever you need it most.

Evaporative Coolers

These walls are commonly referred to as evaporative coolers. They’re the least common type of cooling system that can keep a greenhouse’s temperature below 20 degrees Fahrenheit.

Evaporative cooling is a technique that uses heat to reduce the temperature inside the greenhouse. It prevents plants from getting too hot and dry. It’s important to make sure that the pads are filled with enough water to properly function.

Watering the Plants

Watering your plants may appear to be a simple task. In excessive heat, though, watering your plants requires special caution. Here are some of our best plant watering suggestions:

  1. In the morning, water the plants. If excessive heat is expected the next day, start watering the night before and in the morning.
  2. Check the amount of water the plant is receiving. Determine how many inches of soggy soil surround the plant by taking a measurement. Your plants are dehydrated if water sits on top of the soil. The plants have been well watered if the water has soaked the soil an inch to two inches deep.
  3. Slowly water your plants. This ensures that the water reaches the roots of the plant and does not evaporate.
  4. What does the plant appear to be like? Is the plant’s foliage wilted? You have either overwatered the plant or not watered it sufficiently if it has seen better days.
  5. If you know you won’t be able to water the plant on a certain day of the week, spritz it with antidesiccant. This should only be done as a last resort.

FYI: Antidesiccant is an unique spray that keeps plants moist for longer periods of time indoors than water.


This summer, keep in mind that there are various ways to keep your greenhouse cool. However, first, make sure that you have a good routine and that you keep having fun.

As always, we’d love to know how you keep your greenhouses – and tunnels – cool in the summer, especially if you cultivate in a hotter climate. Please let us know in the comments section below.

Recent Posts