If you’ve got a polytunnel, the first question you’ll probably ask is, “Do polytunnels stay warm in winter?” Luckily, there are many ways to heat up your polytunnel and keep it comfortable in winter. There are ways to keep it cool, insulate it, and protect it from draughts.
Heat up a polytunnel
Winter gardening can be a challenge for gardeners, but a polytunnel can provide a microclimate that is ideal for your crops. The plastic covering of a polytunnel has air bubbles that keep heat inside. They also help prevent warm air from escaping the tunnel. The larger these bubbles are, the more heat they can retain. Besides insulating the tunnel, removing snow from the polytunnel also reduces heat loss.
Alternatively, bubble wrap can be hung from the doors of the polytunnel to trap in heat. This material can be hung by strings, and it helps retain heat inside the planted area. It is especially useful if you use horticultural bubble wrap, as it is UV stabilised and extra hardwearing. It can also protect ceramic pots from cracking. You can also use it to insulate doors and windows.
If you want to keep your plants warm in winter, you can install a layer of bubble wrap inside your polytunnel. The bubbles will help insulate the polythene cover and also block icy draughts. You can tie the bubble wrap with a string to keep it in place. It is advisable to use horticultural bubble wrap which is UV stabilised and tough. The larger the bubbles, the better as they let more light in.
A polytunnel is an excellent place for growing plants in winter. However, if you live in a warmer area, you can use an unheated one. However, it is important to bear in mind that sunlight can increase the temperature of a polytunnel so you must ensure that the polytunnel isn’t too hot, especially during the summer. Furthermore, an uninsulated polytunnel will quickly cool down at night, so you may need to install a heating system.
Keep it cool
One way to keep polytunnels cool in Winter is to place rocks around the edges. These rocks absorb the Sun’s heat and keep it inside the tunnel. Then, you should place a dark-coloured water within the tunnel to store heat and release it slowly at night. You can also cover tender plants with horticultural fleece or sheets of newspaper.
Another simple way to keep polytunnels cool in winter is to place large rocks at regular intervals along both sides. These will absorb the winter sun and retain it.
Protect it from draughts
During winter, draughts and wind can damage polytunnels. However, you can protect them by insulating them from the elements. There are many ways to do this. The most basic way is to place a polytunnel on a flat and sheltered surface. You can also take advantage of surrounding trees and buildings to create shelter.
You can use bubble wrap to prevent draughts and keep heat in. The bubbles should be large enough to keep out cold, but they should still be large enough to let some light in. Place a layer of bubble wrap inside the polytunnel and tie it with string. Be sure to use UV stabilised, purpose-made horticultural bubble wrap.
Protecting polytunnels from dreasts is a necessary step for the greenhouse to function properly. A polytunnel can last as long as 15-20 years. However, you need to replace the cover every few years. Make sure that you place the polytunnel in a sheltered area so that it doesn’t get damaged by wind. Also, make sure that you keep the polytunnel clean to improve sunlight and heat retention. You can even use ladybugs to control pests.
Plants that grow well in a polytunnel
Plants that grow well in polytunnelling include vegetables, flowers and fruit. They should grow quickly and be healthy, and they should be resistant to diseases and pests, unlike outside plants. You can even choose plants that thrive in rain. These vegetables, herbs and fruits will help to maintain the soil’s moisture levels, and they’re also good for deterring pests.
Almost any crop can be grown in a polytunnel, but you should consider the climate and soil conditions in which you live before choosing a crop. For instance, if you live in an area that experiences a long winter, consider planting broad beans. Once the plants have established, they won’t require much maintenance and will produce delicious fruit every year. Other low-maintenance, but tasty vegetables that grow well in polytunnels include strawberries and currant bushes.