▷ What Material Should I Use for My Greenhouse Covering?
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What Material Should I Use for My Greenhouse Covering?

Written by Alan Ray and updated on March 13, 2018
Ben-Greenhouse Plastics-Master

Good Question

Here's a question we'll wager you've probably never been asked.  What do you get when you combine a physician, a cucumber, and an Emperor of Rome?  A strange query, no doubt.  But before you get too humorously creative, we're going to give you the answer.  And that answer is, a greenhouse.  That's right, a greenhouse. 

A Bit o' History

Legend contends that around 30 A.D. Emperor Tiberius' physicians recommend Tiberius eat one cucumber a day to maintain his health. It was no secret Tiberius was a great lover of cucurbits (kyoo-cur-bits) which are gourds in the family of melons, squash, zucchini and others.

The problem, of course, was where to get fresh cucurbita (plural form) in the dead of winter.The Emperor's engineers went to work on that problem and devised the first specularia or Roman Greenhouse.

The first greenhouses were constructed atop open carts where they could be wheeled indoors and out commensurate with the weather. These carts were often framed using mica, a translucent silicate mineral thin enough for light to pass through.  Greenhouse materials have come a long way since then.

Fast Forward To The Past

It took 1700-hundred years before the greenhouse reached the shores of  America. Wealthy store merchant, Andrew Faneuil, is credited with building the first greenhouse in Boston, Massachusetts, way back in 1737. 

Glass Greenhouses

In the last century, the great majority of greenhouses were covered in glass panels. Glass provided the perfect medium for indoor plant growing by keeping plants warm, weather-proofed, and bathed in constant sunlight.

Protected from the elements, vegetables, shrubs, flowers and even trees, could be grown year-round. This was of tremendous benefit to those living in parts of the world with shortened growing seasons or those people who enjoy puttering in the garden during those rainy or cold, wintry months.

Good as glass is at insulation and allowing light to enter the grow room, it is not without its drawbacks.  Glass is susceptible to being cracked or broken by falling limbs, flying birds or just bad luck. Glass also requires resealing each time a panel is removed and replaced to ensure there are no leaks which can be time consuming and costly.

Then and Now

Let's jump ahead to the 21st century and the modern day greenhouse. Greenhouses of today serve the same purpose as those original houses of ancient Rome, only much more efficiently. Next to design, the most obvious difference is the advancement made in the materials used to cover today's greenhouse.

While glass undoubtedly has an army of benefits, it is gradually being usurped in many greenhouses by sheets of polymer plastics.

Plastic Replaces Mica and Glass

With the advent of plastic film, greenhouses have attained new levels of efficacy.  Many of today's greenhouses being built use various types of plastics as their sheath or covering.

Greenhouse plastic or greenhouse film as it is also known, offers the buyer more options than standard glass panels do. Lightweight, cheaper, and less likely to break or crack, these newer plastics come in sheets rather than separate panels and are becoming the greenhouse covering of choice for many home gardeners.

Let's take a look at four of the most popular and commonly used greenhouse films.


Polyethylene plastic is popular with gardeners because it is lightweight and effective.  Polyethylene comes in two thicknesses which are measured in millimeters.  There is a utility-grade for the backyard gardener and a thicker, more durable version known as commercial-grade for industrial applications.

Polyethylene is a popular choice but only lasts a year or two according to the experts.  One advantage of this type plastic is that small rips or tears can be readily patched up using a poly repair-kit.


Copolymer plastic is a step above polyethylene and is more durable and longer lasting than the aforementioned. Two to three years of good use is not uncommon. The constant freezing and thawing, heating and cooling, will eventually cause the plastic to become brittle though and cracking can occur. Higher grade copolymers are available that will last longer but they will also cost you more money.


Polyvinyl is an even better grade of plastic, more durable and longer lasting than the previous two plastics and as you might suspect, costs more to buy.  As a stronger grade of plastic, polyvinyl can last five-years or longer with regular maintenance and care. Polyvinyl is a favorite with gardeners who want a high-grade covering over their greenhouse that requires little maintenance.


Most users agree Polycarbonate is the most durable plastic for home gardening greenhouses. This greenhouse film covering is a double thick or twin-walled polyethylene plastic.

It's extra thickness allows for better retention of heat and humidity thus creating the perfect environment for indoor gardening. Its extra sturdy construction means you won't have to replace this plastic sheeting for at least a decade with proper maintenance.

In Closing

If you're considering a greenhouse in which to grow your favorite plants, be sure to check out all the options available to you with plastics sheets in lieu of glass panels. Plastic sheeting is less expensive than glass, is easier to maintain and is quickly repairable should the need arise. Another perk is that you can fix small tears and cracks yourself.

There are lots of companies that offer greenhouse plastic coverings to fit nearly any budget or cover any size greenhouse. Naturally, prices vary according to the quality of the plastic and the amount used. If you only have a small greenhouse you can buy a medium grade film that will give your indoor garden all the protection it needs while not requiring you to open a Line-of-Credit at the bank to construct.

Some suppliers even offer a white overwintering film designed for those colder months and also a clear overwintering plastic that allows in a bit more light. There are also standard greenhouse films available online and at many of your local garden centers and nurseries.

Thanks for reading and good luck!

About the author

    Alan Ray

    Alan Ray is an independent writer who has experienced an eclectic career. He co-created and was the Head Writer for a reality television series as well as composing and producing the Theme song. He has written radio comedy, specials for National Public Radio, hundreds of blogs and no end of gardening and how-to articles spanning a galaxy of topics from aquaponics to the history of the flush toilet. He has also worked tirelessly on countless projects that went nowhere.Additionally, Alan spent years in recording studios in Nashville, Tennessee, where he worked as a staff songwriter for various music publishing companies. He is both a multiple BMI Award recipient and ASCAP award-winning songwriter, respectively. He has also written 5 books and is a New York Times best selling author (Non-Fiction/Humor). While touring the country doing book-signings, he did over 700 live radio interviews with every major radio station in the nation as well as the BBC and Radio Free Europe.Currently, he is a regular contributor to this site in addition to two of the top gardening magazines in Canada including a Medical Marijuana magazine and also a B2B mag.He enjoys small town life in southern Tennessee where his time is spent writing, messing with plants and laughing a lot with his lovely and quick-witted wife.


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