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Does A Greenhouse Roof Need To Be Clear?

A greenhouse can be a great asset to any grower, whether it is used for growing produce such as fruits and vegetables or even for growing such plants as flowers or cultivating trees. There are many different greenhouse designs, but when it comes to the roof, which material is best? Does a greenhouse roof need to be clear?

A greenhouse roof does not need to be clear. The transparency of a greenhouse roof should be determined by which plants are grown within the greenhouse. Some plants require more or less sunlight. A greenhouse roof should be clear or opaque based on the requirements of the plants growing within.

The roof of a greenhouse is a vital component of the structure. It usually defines how much sunlight is allowed into the greenhouse, which directly affects how well the plants inside of the greenhouse grow. Let’s take a look at whether or not a greenhouse roof needs to be clear and what the alternatives are.

Does A Greenhouse Roof Need To Be Clear?

Greenhouses are vital for every grower who wants to extend the growing season of their favorite crops or for those who are required to grow certain plants out of season.

Using a greenhouse to grow crops and other plants allows a grower to cultivate the perfect environment for the plants. This maximized the growth of the plants, decreases growing time, and significantly increases plant health which directly results in a greater yield from the plants.

However, for a greenhouse to be as effective as possible, it must be well constructed and constructed from the right materials for the plants that will be grown within.

The material that a greenhouse is made from determines how much sunlight enters the greenhouse, how warm or cool the greenhouse is, how sturdy the greenhouse is, and how well plants will grow inside of it.

This leads many to wonder if a greenhouse roof needs to be clear?

The truth is, glass is no longer the best material available for greenhouse roofs, and there are other materials that allow a greenhouse to be better focussed on growing certain plants and for successful cultivation in specific climates.

A greenhouse does not have to be clear. It can be clear, but it can also be opaque. It all depends on what will be growing within the greenhouse and how harsh the external environment is.

A clear roof will allow more sunlight in, which is ideal for some plants, but others require less sunlight for optimum growth, which can be achieved by using an opaque roof.

In this video it is not recommended to get a completely clear roof for a greenhouse:

What Are The Alternatives To A Clear Greenhouse Roof?

Many greenhouses are built with a clear or fully transparent roof, and many growers believe this to be the best possible option for a greenhouse roof.

However, the truth is that a clear roof is not always the best option for a greenhouse roof.

A clear roof is great for plants that require full sun or for greenhouses in climates that are not very sunny, but a clear roof can mean too much sunlight in some parts of the world, which may do more harm than good to the plants within it.

  • Alternatives to clear greenhouse roofs are opaque greenhouse roofs.
  • An opaque rood may be made from various heavy-duty plastics or from frosted glass.

Opaque greenhouse roofs have many benefits, but the main reason why they are beneficial is that they diffuse sunlight. Diffused sunlight is far less harsh on growing plants than direct sunlight, especially in very hot climates.

Greenhouse roofing material can be clear or opaque, and both are as sturdy and stable as each other, providing equal protection from the outside environment if they are installed correctly. Clear roofs are made from glass or clear perspex, but they are not always ideal.

Opaque greenhouse roofs are made from various plastics and can be made to fit any greenhouse design.

Other alternatives such as solid metal and wood are not ideal for greenhouses, as they do not allow any sunlight whatsoever, but an opaque roof that diffuses sunlight is ideal for many plants.

Here’s a video talking about some benefits of polycarbonate material:

What Are The Benefits Of Clear Greenhouse Roof?

A clear greenhouse roof is not the only option, but it is ideal for growing certain plants and for greenhouses that are designed with specific weather conditions in mind.

There are, however, some important benefits that come along with a clear greenhouse roof, but it all depends on what is grown within the greenhouse.

Some benefits of a clear greenhouse roof are:

  • Maximum Sunlight – a clear roof allows for the maximum amount of sunlight to enter the greenhouse while still maintaining a controlled environment within the greenhouse and providing good protection for the pants inside, especially in cold or constantly overcast regions of the world.
  • Increased Heat – the high amount of sunlight that enters through a clear roof heats the interior of a greenhouse very effectively. High temperatures are ideal for some species of plants, and this makes a clear roof ideal.
  • Perfect For Seedlings – direct sunlight from a clear roof is perfect for cultivating seedlings, as direct sunlight promotes germination. High heat and direct sunlight, along with plenty of water, is the best environment for quickly producing plants from seeds.
  • Humidity – the high heat and direct sunlight that comes with a clear roof create a lot of humidity within a greenhouse. This is the perfect environment for many plant species.

What Are The Benefits Of An Opaque Greenhouse Roof?

Having a clear roof for a greenhouse can be ideal in the right conditions and fr the right plants, but there are plants that grow far better under an opaque greenhouse roof.

Opaque roofs are just as sturdy and provide as much protection as clear greenhouse roofs, but they have their own set of benefits as well:

  • Diffused Sunlight – some plants require full sunlight, but the majority of plants, especially food crops, grow far better in diffused sunlight, direct sunlight can be harsh and more damaging to plants than good, and diffused sunlight is far safer and less damaging, while still allowing the plants within to grow well.
  • Better Environment Control – the diffused sunlight also allows for better environmental control within the greenhouse. Controlling temperature, humidity, and amount of sunlight are all keys to successful plant growth within a greenhouse.
  • Good For Maturing Plants – the diffused sunlight and improved environmental control that come with an opaque greenhouse roof produce a better environment for maturing plants. Direct sunlight is better for seedlings, but diffused sunlight is better for cultivating healthy plants long-term.


The roof of a greenhouse is a vital component of the structure and directly contributes to how well plants grow within the greenhouse, but there are various roofing designs and materials that are best for specific plants.

A greenhouse roof does not need to be clear. A clear roof has its benefits, such as direct sunlight for seedlings (source), but opaque roofs are an option as well. Opaque roofs provide diffused sunlight which is better for environmental control within the greenhouse.

Whatever roof material you choose for a greenhouse, be sure that it is the optimum material (source) for the sunlight, temperature, and humidity that your plants need, and you will find that the roof will help improve the plant growth significantly!

Choose the greenhouse roof based on the plants, or grow plants based on the transparency roof, and you will have a far more successful greenhouse!

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