Greenhouse Material: Getting the Perfect Fit

by Christina Molcillo June 04, 2019

Greenhouse Material: Getting the Perfect Fit

Historically, greenhouses were architectural glass walled masterpieces, such as l’Orangerie at Versailles in the late 1600’s, and any number of glass and wrought iron Victorian conservatories throughout London. While beautiful, glass greenhouses were often ineffective, with a high heat transfer rate that allows cold air in during winter months, and too much light in the summer months which could cause plants to overheat. During harsh weather, such as high winds or hail, the glass would often break, spoiling the enclosed environment meant to protect the plants inside.

Fast forward almost 400 years, and most commercial and personal greenhouses use materials such as polyvinyl chloride, fiberglass, double-sheet polyethylene, and polycarbonate. The benefit for all these choices is the price point, durability, ability to control the amount of light and overall internal environment.

Poly covered greenhouse ready for growing

While glass greenhouses are aesthetically pleasing, the benefits of using a poly greenhouse cover far surpass the loss of having a ‘pretty’ greenhouse; you’ll have beautiful plants to show for it! Poly covers are far more durable than glass, and can withstand extreme weather events that glass cannot. Weather patterns change with the seasons, and while glass covered greenhouses will often become too hot in the summer, and too cold in winter, greenhouses that use a woven poly cover will be able to adapt. During the heat of the summer, the fabric lets in a measured amount of sunlight, keeping the plants from overheating. In the cold of the winter, these covers retain the heat efficiently, keeping the frost at bay. For growers who want to use light dep methods to create their own cycle of seasons, fitting a blackout tarp over the greenhouse is easy to do.

Overall, the winning argument for a poly greenhouse cover is economics. On average, glass for a greenhouse will cost around $2.50 per square foot, while poly will have a median price of .25 cents a square foot. Add this to the fact that poly covers can reduce the heating costs in your greenhouse by up to 40% and the bottom line is undeniable – poly greenhouse covers are best for your plants and better for your wallet.

Poly covered greenhouse with happy plants

But what type of greenhouse poly is the best for your greenhouse application? Let’s go over some of the different types of poly materials available at Left Coast Wholesale.

Duraweave 150 8 Mil Poly

Left Coast Wholesale’s Duraweave 150 is an in-house woven poly cover in 8-mil thickness. The woven construction is durable, easy to handle, and features an 88% light transmission in greenhouse environments. Duraweave 150 8 Mil is a great option for hoop houses, high tunnel greenhouses, and large pre-fabricated greenhouses which utilize poly as a covering. This 8 Mil Poly is graded to last up to four years under normal climate and growing conditions.

6 Mil Poly


Left Coast Wholesale’s 6-Mil poly covers feature exclusive coatings to maintain superior light diffusion which improves overall coverage and distribution of incoming light in your greenhouse. The diffused poly stock is a great option for all greenhouse styles, at a great price. 6 Mil diffused Poly from Left Coast is graded to last two years under normal growing conditions.


Left Coast Wholesale offers a unique 6 Mil Poly stock specially designed to improve consistency and maintain optimal growing conditions by utilizing a special coating on either side of the poly. The inside layer is coated with an anti-condensation or anti-drip coating to prevent moisture from gathering on the sidewalls of a greenhouse, causing moisture to drip down the walls and into the ground where it can be absorbed. This coating prevents water droplets due to humidity from landing on plants at night.  The outside layer has a coating that prevents dust from adhering to the outside of the greenhouse, which can significantly impact light transmission. This poly stock is graded for a lifespan of two years with a rating of 90% light transmission.

Poly covered greenhouse with plants ready to harvest

Duramax 200 12 Mil Poly

Left Coast Wholesale Duramax 200 is a poly woven style greenhouse material. With a higher thread count per linear inch, you can provide more shade into your green house. The Duramax 200 is a 12 Mil poly weave and offers 85% light transmission.

Shade Cloth

Left Coast Wholesale offers 40% Shade Cloth, which can provide a 40% reduction incoming light to retain cooler temperatures in extreme heat environments and situations. Constructed from high density polypropylene, the cloth protects against wind, hail and UV. Highly Resistant to rips, tears, and fraying.

Blackout Material

Blackout Material is Black on one side and white on the other - this allows for growers to trigger the flowering stage and control the light schedule the plants receive to induce and support the flowering cycle. If a plant receives too much light during the flowering phase it can affect the development and maturing of flower sites. Light derivation takes advantage of a plants photoperiodism capabilities, forcing it to flower much sooner than it normally would.

Custom Greenhouse Covers

When you’ve decided what you need, Left Coast Wholesale can cater to your exact needs when it comes to greenhouse covers. They offer custom cut sizes in 5 and 6 Mil Clear, 9 Mil, 10 Mil and 12 Mil Poly Weave, as well as a 12 Mil Black and White Light Deprivation cover. 

The science behind successful greenhouses has come a long way since the 1600’s, and Left Coast Wholesale is proud to offer the latest, and most economical, breakthroughs. No matter the size of your grow, Left Coast has you covered.

To find out more about our Pre-Cut Poly, receive pricing, or get greenhouse poly into your store, send an email at, or give us a call at 800.681.1757 today!

Christina Molcillo
Christina Molcillo


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