Appalachian folklore has a strong mixture of European, Native American (especially Cherokee), and Biblical influences. The Cherokee taught the region's early European pioneers how to plant and cultivate crops such as corn and squash and how to find edible plants such as ramps. The Cherokee also passed along their knowledge of the medicinal properties of hundreds of native herbs and roots, and how to prepare tonics from such plants. Before the introduction of modern agricultural techniques in the region in the 1930s and 1940s, many Appalachian farmers followed the Biblical tradition of planting by "the signs", such as the phases of the moon, or when certain weather conditions occurred.