Growing in Polytunnels - an introduction - revised with Hans Wieland €75 A polytunnel is the best addition to any garden. It provides early season produce like early potatoes and spring onions. You can grow more exotic vegetable crops like tomatoes, cucumbers, peppers and aubergines and herbs like coriander, basil and tarragon. A polytunnel also extends the season for many crops and provides something to harvest all year round. A tour of the centre's many tunnels will show various sizes and give advice on how to erect a tunnel. We will also cover ground preparation, growing systems and rotation, propagation and soil fertility management, pest and disease prevention and control.