Intensively used gardens suffer because of crop rotation and soil exhaustion. Carrots, roses, strawberries and fruit no longer want to grow, neither do many types of vegetables. Parasitic roundworms or nematodes are the cause. Fight these problems with the most effective Marigold variety 'Single Gold'. It can also be used as an organic green manure. The pests penetrate into the roots and are thus almost completely killed. The 60 cm tall plants bloom and look gorgeous. After freezing, the plant material is composted. It adds beneficial nutrients to the soil.