A polytunnel is a tunnel made of polyethylene used to grow plants that require a higher temperature and/or humidity than that which is available in the environment.
Polytunnels are mainly used in temperate regions. They are similar in principle to greenhouses and cloches (row covers). Modern designs allow sowing and harvesting machines to move inside the structures so as to automate production.
Polytunnels have had a significant effect on the production of strawberries in the United Kingdom. Other soft fruits such as raspberries and blackberries are also cultivated in the same way.