Snow on a polytunnel is not a problem for some structures, while for others, it may lead to damages. During cold months, it is worth checking every now and then how the greenhouse is coping. Soon winter will make its presence felt. Even though cultivation is on hold, it is important to properly prepare the construction for the winter, and monitor it during this harsh time. In this Krosagro guide , we will advice on how to take care of a polytunnel in winter, how to protect the structure from snow load and avoid damage.
Frame of a foil tunnel
The frame of a greenhouse will show different strength parameters and will be made of different types of material, depending on the manufacturer. PVC and aluminum constructions will perform in spring and summer, but with less comfortable conditions outside, such greenhouses should be dismantled.
Autumn gusts combined with heavy rainfall can lead to structure distortion and even breakage. Regarding garden tunnels made of steel, gardeners have more time to grow. With light snowfall, structure and cover can remain in the garden without any damage. However, if the construction is located where snow often falls and in big quantity, there are still several ways to grow plants all year round.
A year-round polytunnel
To avoid snow related problems, it is worth using a few solutions for foil and construction to last during winter. One solution is to remove the cover from the frame. Of course, plants still growing might not be able to survive while exposed to difficult conditions. The foil applied to the structure creates a shield on both sides. The wind applies pressure on it over and over again. A solid steel frame will withstand it, but you should be careful when snow is on top of the structure.
With small amounts, snow should fall from the tunnel by itself (gothic construction). However, if the frame starts to accumulate it, remove the excess. Snow beginning to melt and then freeze is the biggest threat. The weight of this ice load is significant. The bigger it is, the more likely it is to break through. By keeping a positive temperature under cover, you will prevent snow from gathering, and contribute to melting.
Heating a foil tunnel
Cultivation under cover is carried out in both hobby and professional polytunnels. Some gardeners use heating systems. If the greenhouse is located near a house, you can connect fans, ventilator, oil or electric heaters, etc. It is worth ensuring safety and sealing of joints and doors. It should be remembered that in the greenhouse, moisture concentration vary and extension leads and other devices must be suitable for use in the garden. Heating the greenhouse gives the opportunity to operate during winter. There are quite a few edible plants able to mature with minimal heat. Gardeners do not have to give up on their hobby during the cold period. They can continue to enjoy fresh vegetables and fruits.
Shape of the foil tunnel
Tunnel shapes also influence the effect of snow on structures. Browsing the wide range of greenhouses available on the market, many of them differ with their design. They are available in semi-circular, gothic, arched, etc. The most adapted shape for winter is the gothic one. Semi circular roofs with two slopes and straight side walls allow snow to accumulate. And when piles of snow end up on both sides on the ground, they have to be evacuated. A thick layer would limit light transmission and what is linked to it : heat.
Galvanized garden greenhouse
Structural steel elements are in contact with moisture resulting from cultivation, watering, as well as constant contact with the ground. Some parts, like cranks and door frames, are constantly exposed to weather conditions. To prevent corrosion, polytunnel steel structures are covered with a layer of zinc. For most Krosagro tunnels, the protection process used is hot dip galvanization. Thanks to this, the coating fully adheres to pipes and profiles, protecting elements from corrosion. Structures are reliable for years, and cyclical maintenance means that gardeners are able to cultivate under cover on the long term.
Plastic cover for tunnel
The cover is an element of a garden greenhouse that requires good preparation for winter. Foil for a garden tunnel should be durable and solid, and also adapted to protect plants in winter. When purchasing a greenhouse, it is worth checking its properties. Usually you will find the designations UV2, UV4, UV5, UV8, etc. The number shows how many seasons the foil will be effective for. One season means half a year, so UV2 is a foil for a year, and UV5 for two and a half years, etc. The higher the number, the more robust the material, and the higher the price.
Foils for cultivation under cover should properly fit the frame. Plastic clips are used to secure the plastic film to the structure. This method is often combined with the use of duck tape, fixing the foil on the entire length of the arches. A tight cover enables to withstand difficult weather conditions, including snowfall.
Crops under cover in winter
Snow on a polytunnel is no longer a problem. Having well protected and constructed your greenhouse, you can be sure that your investment will be profitable. Although every product has a guarantee ensuring exchange or refund, there is no compensation for the time spent cultivating the plants. Post purchase disappointment is very discouraging. To avoid unpleasant situations, it is worth choosing a hot-dip galvanized polytunnel, directly from a European manufacturer. Robust and durable, adapted to the local atmospheric conditions, it will provide year-round cultivation under cover.