Every year, farmers recover from their harvest the best seeds, i.e. those that have best adapted to local growing conditions (climate, soil, etc.) and whose plants produce the best fruits and vegetables. This selection of seeds will be replanted the following year and used for the next harvest. The interest of this practice is to have over the years more and more resistant and region-specific plants. Thus was born the butternut squash Kouign Amman which grows on only a few hectares of land in Brittany.
In 1981, prohibition to market seeds and plants not registered in the European catalog.