Humans have cultivated approximately 400,000 kinds of crop plants over the past 12,000 years. However, only a small number of these are grown worldwide today, mostly as monoculture. This results in the loss of important crop plants and their genetic material. Many of the endangered crop plants are particularly resistant to pests and climate change, which is why growing these old varieties is often worthwhile for hobby gardeners. Mixed crops are also economical because they keep weeds, diseases and pests from proliferating. Varied harvest times ensure that the soil is permanently shaded and stays moist longer. It is important that the combined plant varieties complement each other. The exhibits show examples of monocultures and suitable mixed cultures.