Best Greenhouse Covering For Extreme Weather

Polycarbonate glazing has proven to be the Best Greenhouse for Hail, Wind, Snow and Cold Temperatures

Impact Resistance 200 Times Greater Than Glassbest greenhouse for hail and snow

People claim the weather is unpredictable these days, especially in the Rocky Mountains.

I call shenanigans.

…It is predictable…

in its unpredictability –  It will hail…it will snow…it will get windy…and that’s where polycarbonate as a greenhouse covering comes in. 

When a rainstorm takes a turn and starts to unleash hail disguised as golf balls, you want to know that your greenhouse and the fruits of your labor inside will be adequately protected.


best greenhouse covering
“Mr. and Ms. Clarence Costner proudly display baseball-sized hail that fell on their farm near Norbonne, Missouri date unknown. Photo from Weatherwise Magazine, August 1976.”

A local CSA program shut down here a few years ago after they lost their entire crop to an early summer hail storm. I also remember when the Archuleta County Fair, held at the end of July/beginning of August, was bombarded by several inches of hail within a matter of minutes.

It comes fast, hard, seemingly out of nowhere, and can devastate a garden or greenhouse.

Thankfully polycarbonate is strong.hail resistant

I mean, it’s really strong stuff. It’s merits go beyond its strength, but when it comes to creating a strong protective greenhouse covering, polycarbonate is virtually unbreakable.

For example, read A&C Plastics product details on multiwall polycarbonate, “Multiwall co-extruded thermoglazing has a high impact resistance – 200 times greater than glass and 10 times greater than acrylic. A Multiwall 8mm panel is so strong it can withstand the impact of a 16 lb. weight, falling 25 feet onto the panel, with no breakage. It will maintain its impact strength over a wide temperature range from -40° F to 250° F.”  And by the way, we offer both 8mm and 16mm multi-wall polycarbonate!American Made

A 16 lb.weight falling 25 feet – no breakage.

I don’t know what the world record is for hail…

…ok, I just looked it up. I think we’ll be alright, at least polycarbonate protected gardens will be.

“The largest officially recognized hailstone on record to have been ‘captured’ in the U.S. was that which fell near Vivian, South Dakota last summer (2010) on July 23rd. It measured 8.0” in diameter, 18 ½” in circumference, and weighed in at 1.9375 pounds. Mr. Lee Scott, who collected, the monster stone originally planned to make daiquiris out of the hailstone but fortunately thought better and placed it in a freezer before turning it over to the National Weather Service for certification.”

best greenhouse covering
The largest official hailstone ever collected in the U.S. An eight-inch monster that fell at Vivian, South Dakota on July 23, 2010.

The largest official hailstone ever collected – weighing in at 1.9375 pounds. Not even close to a 16 pound weight.

We all know the damage that even an average hail storm can bring.

best greenhouse covering
Garfield Park Conservatory


best greenhouse covering 4
Squash Blossom Farm after the storm.

Thankfully polycarbonate is strong, it will hold up to hail damage, and ultimately keep your garden safe and protected.withstands snow

That’s why, in my humble opinion, the polycarbonate we use in our Growing Dome® Kits…

Is The Best Greenhouse Covering

For Unpredictable Weather

From John & Barbara Eychaner in Banner, Wyoming

“No damage to Growing Dome solar greenhouse after hailstorm. In mid-afternoon on May 26, 2013 we had quite a hail storm. I was not home but my husband was. Some of the hailstones were close to softball-baseball size which, of course, did lots of damage. We have had to have our house roof completely replaced, the three skylights on the house and the rain gutter. We have to say the rain gutter damaged on the house was plastic/fiber glass. There were large holes in that. We also have a good sized steel pole building with again the fiber glass along the peak for light purposes. There are several large holes in that. This will all be replaced. But, Praise the Lord! There was NO hail damage to our geodesic 22 foot Growing Dome greenhouse from Growing Spaces. We frankly were surprised. We highly recommend the Growing Spaces to anyone interested in a solar greenhouse.”

polycarbonate greenhouse covering
Look at all that Poly

You know the saying. The one credited to Samuel Clemens. And I know it’s not just Pagosa Springs that claims this humorous and sometimes frustrating trait.

“If you don’t like the weather… wait 5 minutes. ”

But in that 5 minutes alone, don’t let the power of a Rocky Mountain hailstorm destroy your dream garden!

Please contact us if you’d like to get more information on Growing Domes.  Or to receive more informative gardening and Growing Dome articles, please sign up for our monthly Newsletter “The Happy Grower”

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  • Never thought about hail as a problem for the dome. Probably should have as I had to replace the siding on our little house next to the dome due to a hail storm . Living in Missouri we have alot of hail storms and they don’t effect the dome at all.

  • Interested in purchasing a green house dome. Please send details about sizes and price list, and assembly ie can a strong woman put one up by herself?! Thanks.

    • Hello Janava Dharmadeva, we have two different types of Polycarbonate. Each handle the cold differently. The twin wall glazing is 8mm thick and will keep the Growing Dome 10-20°F warmer than the outside temperature, where the multi-wall glazing is twice as thick (16mm) and will maintain at least 25°F than the outside temperature.

  • We only had trouble with hail on a 15 year old twin wall Growing Dome. My husband (founder) never lets one die, and we have always been experimenting, maintaining, or re-cycling Growing Domes, to keep gardens going for many. It is interesting living with an inventor. But, at least I can say, this article shows one of the major concerns for us being a Colorado Based Business…..and we are so happy that product excellence is partly due to the quality of our glazing. Same vendor for many years. Great relationship. We are always studying ways to make things last. Thanks, Jason!

    • P.S. I remember seeing hail for the first time when we visited my Aunt in Denver. This picture could have come from that event! In California, we never had such things, and for me it was a marvel to see balls like this fall from the sky. It made the whole yard white in minutes. Big Thunder too. I was captivated! (small child) Didn’t know the damage it could do til Dad was anxious about his car!

  • I had no idea that polycarbonate could even be considered a covering material. It makes sense that you’d want a strong roof for a greenhouse, and the size of that hail you showed demonstrates that you want it to be able to withstand things like that. There’s a ton of things to consider when it comes to stuff like this, and I appreciated how you talked about the positives of polycarbonates. Thanks for sharing!

  • A great article, Jason. Well written, full of important information, and just fun to read! I never worry about hail or violent storm activity on my domes. They are actually a great spot to tuck into during a quick-rising storm. Love these domes.

  • I am looking to buy a Green house system that has a large space for growing Vegatables, is a automated system and protect against dammage due to hail storms. Please contact me with information about your products.

    • Hello Robert,

      I sent you some information via email. Our greenhouses come with stamped engineered plans for 100mph winds and 60lbs/sq./ft. snow loads. The polycarbonate covering also comes with a 10 year manufacturer warranty for hail damage and yellowing. Check out this link for some more info on our polycarbonate:

      Let us know if you have further questions,


  • Hi Kyle,

    Do you have anything engineered for 160mph + in 42′ diameter. That’s what you need these days in the tropics.

    • Anthony,

      Our standard plans are stamped for 100mph wind loads, Exposure B. With that said, we can have the plans re-engineered for your specific location. Please fill out the Building Department Questionnaire on this webpage: . Once you have the questionnaire filled out, simply fax (970) 731-0198 it to us or scan it and send the image to Engineering costs typically range from $350- $800. Shoot me an email or give us a call (970) 731-2120 if you have further questions,


  • Thanks for sharing these information. Glass requires a very costly and sturdy structural system. But it can last for at least 30 years and and clean glass always allows good light transmission.

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