With our unpredictable weather, there's never been a better time to cultivate vegetables under shelter.Experienced grower, Klaus Laitenberger shows how to use the heat and shelter of a greenhouse or polytunnel to maximise crop production and supply tasty, healthy food throughout the year. He gives full details of sowing, planting, spacing and harvesting for all our best-loved herbs and vegetables, as well as introducing exotic newcomers such as pepino and yacon.