For several decades, a growing number of protohistoric sites in Auvergne (Massif Central, France)—mostly excavated through preventive archaeology—have been subject to the collection of archaeobotanical analysis. This study presents the archaeobotanical results from ten La Tène sites dating from the last five centuries before the Roman conquest. In addition to providing an inventory of taxa, this paper concerns crops and crop cultivation methods. These results are interpreted in a wider context, dealing with crop husbandry, arable farming, storage and consumption practices. The sites are located in the Limagne plain within a 50-km radius around the city of Clermont-Ferrand. A total of 23,579 carpological remains were identified from 163 sediment samples totalizing a volume of 1096 l. Comparable to other sites in Gaul, the spectrum of cereals and pulses is restricted. Spelt (Triticum spelta), einkorn (Triticum monococcum) and foxtail millet (Setaria italica) are disappearing or becoming rare. A better control of agricultural techniques and increased yields is supposed during the ca. five centuries of the La Tène period. Mixed cultivation is hereby replaced by the sowing of monocrops. At the beginning of this period, farming systems are dominated by a polyculture of cereals and pulses. They become more specialized during the last two centuries before the Roman conquest; diversity of cereals and pulses is decreased.