The life of your greenhouse rests on its covering— also called its shell, skin, or film. This applies whether your covering is poly, plastic, glass, or any other material.
While you can look at your greenhouse like any other building, what makes your greenhouse a greenhouse (and truly functional) is its covering. Take care of your covering, and your greenhouse will keep producing for years and years to come; damage this, however, and your greenhouse hobby or business is stalled until it’s replaced or repaired.
Before this happens, be sure to protect your greenhouse coverings (plastic, glass, or other material) from these top risks.
The sheer force of wind, gusts, and storms is probably the biggest threat of all to greenhouse coverings. Growers with poly tunnels and greenhouses can especially attest to this— but it can apply to glass and other types of greenhouses, too.
Any structure is vulnerable to wind force. But greenhouses (and especially their coverings) can become a chaotic mess under the right wind and conditions, and are way more at risk of damage, complete destruction, and loss.
Poly greenhouses should be tightened, and vents and doors closed, in anticipation of high winds. Plastic should always be attached securely and thoroughly during the building process— and a very tight, solarized greenhouse covering helps with poly. Glass greenhouses and other types should shut any vents, openings, and doors if high winds are expected.
While wind force poses the most direct damage to coverings (in some cases blowing greenhouse shells or skins clear off), debris from wind can be another issue to reckon with. Winds strong enough to pick up debris might send it flying towards your greenhouse, and at speeds strong enough to puncture plastic or shatter glass.
Thankfully this damage can be easy to repair with little harm done to your operation— although if not fixed early enough, rips and cracks lead to bigger problems. If unnoticed or unattended, holes or rips in poly greenhouses will widen or weaken, thus making your structure more vulnerable to wind force. Cracks in glass greenhouses can also unintentionally bring wind gusts into your structure and slowly compromise its integrity, too.
Tree damage brought on by wind is one of the most common causes of actual tree damage. But there are other causes for it, too: such as having a structure close to trees or wooded areas.
While there are some advantages to having a greenhouse built near a forest or tree line, there are definitely some disadvantages, too. The most obvious: any tree, at some point, might fall with or without wind force. And sometimes, trees drop dead or weakened limbs, which may puncture and damage coverings.
If you’re concerned (and live in an especially windy region), you may wish to build your greenhouse farther away from trees. If your greenhouse is already close to one or more trees, keep an eye on them. You can always remove trees and dead limbs if they make you nervous and seem ready to drop.
Cold Temperatures, Snow, and Hail
This risk can surprise greenhouse growers and catches many newcomers off guard. Cold temperatures can have negative effects on greenhouse coverings in many ways, some of them surprising— while elements like snow and hail have more obvious effects.
Clearly, hail may damage a covering or film if it is large enough to puncture or shatter. On the other hand, there is snow load: the weight of enough snow can topple some greenhouses, especially if they are not designed in a certain way (without gothic arches, gutters, etc.). Snow removal, when accumulation is considerable, is highly recommended!
Lastly: for poly growers, if your poly has aged considerably, cold weather (especially subzero temperatures) can completely rupture and shatter greenhouse plastic if condensation on it freezes and then thaws. This is why greenhouse growers should take into account the age of their greenhouse poly heading into the winter before facing cold temperatures in frigid regions.
While less a problem for glass greenhouses (and a potential problem in cold climates), poly greenhouse growers really need to keep track of the age of their poly to prevent damage. If the lifespan of your poly is close to or well past the upper numbers of its manufactured age, it may be time for a replacement before it gets damaged.
Besides cold temperatures and freezing, aged plastic is far more vulnerable to all the top risks to your covering: including wind force, wind debris, tree damage, snow load, and other factors. It won’t hold up against these elements as well and is likely to be punctured, ripped, or completely compromised in any other way much more quickly. Even heat and sun damage can bring aged plastic to its knees!
Again, keeping track of your poly’s age and integrity is important. Before coverings are damaged and set you back, make sure to notice signs of aging, old poly: discoloration, patches, etc. It’s much more judicious to shut down and take the time for a full covering replacement than be inconveniently forced to shut down when it eventually breaks.
When protecting the structural integrity, function, and crops in your greenhouse (as well your profits), be sure to focus on protecting your greenhouse coverings as a big part of your maintenance.
Still, damage to coverings can and does happen. Sometimes it’s inevitable. For full financial protection of your entire structure (including its covering), and to avoid a loss, greenhouse insurance can give you one last needed shield against any possible damage to poly, glass, or other type of greenhouse skin, film, shell, or covering.